I think a lot of it starts with history.  Has SM/SD actually DONE anything to alienate the bride/groom?  Or were they hated at first sight for no good reason.  Next would be degree of exclusion.  Is everyone including the neighbour's first cousin invited except SM/SD?  If BM is invited but not her husband, and BD is invited but not his wife....and then just a witness or two....maybe I could get my head around it.  But if you have more than 6 guests...unless you have been estranged and intend to remain that way - either invite both parents and their spouses, or have separate weddings.

I think having multiple "celebrations" is a great idea.  If BM/BD or SM/SD can't be trusted to behave themselves, then have a separate wedding.  If they hate the air each other breathes - have a small wedding (or elope!) and have a family party at another time.  But trying to throw a traditional wedding when you have a non-traditional family feels like playing make believe.  Let's pretend Dad's not remarried because Mom hates her.  Let's pretend Mom and Dad don't hate each other's existence and get a picture of "my happy family".  Blech.  Just because you're a bride or groom doesn't excuse you from the human obligation to try to be courteous where you can. (edit to add - and all guests should put on their best manners and try to be courteous too!)

And if you can't, then actions have consequences.  If bride/groom insists that SM doesn't come, (and there's not a valid reason for it other than you don't like that she exists), then it shouldn't be a surprise when Dad doesn't come either.  I'm not saying in cases where something truly valid happened (abuse, SM agrees and doesn't want to be there etc.).  But if you're not willing to have her at the wedding, then you shouldn't be willing to have her at Sunday dinner, or Christmas or birthdays either.  In which case - have at it.  But you've chosen who "family" is, and Dad/SM are no longer it. 

Weddings are not the time to choose sides in my opinon.  It's time to celebrate family.  If your guest list detracts from that, maybe just elope and have separate celebrations later so that you're not making a public spectacle of a private matter. 

There are so many factors that could go with these types of situations.

I've been with SO almost 8 years. If/when we get married I would never expect him to not invite his kids and I wouldn't expect them to not be there.

Since I can't predict the future so in x amount of years skids don't want me there... oh well. I don't see that happening but never know. 

BM got married and didn't even tell them she was getting married. She sent them pictures the day after. SD is still hurt by this and it's been 4 years. I am pretty sure it bothered the boys too.

My situation is "better" then others but still difficult I think. 

I seem to read on her wedding drama seems to happen more with older skids (ones that are my age.. I'm 37.. or older) Skids that are getting married for a 2nd and when SMS came in when they were adults... making dynamics different from someone that came along when kids were young. 

Sorry, I forgot to specifically address kids.  I also think that other than a few pictures, SM/SD are only in line of sight and can be expected to behave themselves.  (If they're guaranteed to make a scene I agree with excluding them either completely or by having separate events).

Kids can't be counted on to behave.  Some folks are getting married for the first time, and didn't envision having children at the wedding!  Some kids are young, and even if well behave will demand attention from their parent which can't simply be ignored.  Others are just poorly behaved.  If a child can be counted on to behave and not detract I think they SHOULD be invited.  Unless it's a no kids wedding (across the board, not a single child is invited).

But if the child is well behaved, or if the "child" is an adult that hasn't actually done anything wrong, and a parent wants them there, yes I think SKs should be invited to the wedding.  (Or...same thing....have separate celebrations if the wedding day is so delicate in the mind of the bride/groom that the simple sight of a person will "ruin" their whole day).

IDK....

Me personally, If I did marry this dude (he'd have to do a complete 180, divorce his mini-spouses, drop his militant behavior, delete his disneyland dad parenting, get therapy for his deepset guilt about his divorce 4 years ago, set boundaries with his ex wife, and allow me to run the finances of the household) .... I'd invite everyone but it would be at a location and during a time the skids probably wouldn't be able to make it. 

I honestly wouldn't want his skids around seething in jealousy, having to work my plans around THEIR school schedules, and having to deal with the dude catering to them on MY day. 

SO I'd probably elope/destination wedding with just us two and force him to turn off his phone so his kids cant blow him up every 15 min with trivial questions. 

Also, if I stayed with him (which I'm not) if/when his kids get married I could care less if im invited or not. One less gift I gotta buy and save 3 hours of my time to do something else more conducive to my lifestyle.

It sucks, and I get it. As a future SM, as a divorced BM, and as someone whose father is widowed but healthy (heaven forbid but i could be a future skid!), it sucks. There are certain unpleasant realities when it comes to non-intact families. The biggest being not seeing your kids every day as a divorced parent. You can't "have it all" in terms of the big happy family. The more classy (by that i mean emotionally, not financially) those involved are, the closer you can come, i guess. ETA vacations are another issue. If you want to go on vacation with your kids, are you obligated to bring skids, too? My SO has 4 kids and vacations with some of them really suck. Two are prone to screaming tantrums. One likes to come to dinner with her nipples showing. Every night, even after being discreetly asked to cover up, and she's 26. I used to look forward to holidays and vacations, as well as family milestones, now it's fraught with minefields. SO used to love having his kids in bed with him, like 6 people on one mattress. We all give things up when dealing with step-dynamics. It's hard. 

as MissK03 said. 

DH and I had a small garden wedding. All of his kids (and mine) were invited. We paid flights for those out of state and paid accomodations. Four of the five attended...Mini Wife (oldest daughter) declined the invite and later said, "well, you just got married in someone's back yard" to excuse her declining attending.  Little did I know she was just beginning her war against our marriage, that being her first "hit." Regardless, photos were taken that included everyone. No "this group" and "that group;" just "normal" wedding pictures.

Fast forward to 12 years later. A final event where I had enough of toxic treatment and completely disengaged from DHs kids. DH sees his kids away from our home. I'm good with that. Then out of the blue....I got invited to his oldest son's wedding!!! Let's forget that the asshole caused me much grief 5 years earlier and never made one attempt at rectifying the mess he started. Never mind I told the asshole to leave me alone. Did I attend? Absolutely NOT.  Why? To be subjected to his (and the other siblings) BS behaviors? Nah. I'm good right here at home.

So, this is a topic that is not cut and dry. And I'd dare say, StepMoms are more often slighted /insulted in these "wedding" situations than the SM being the asshole. DHs kids were NEVER excluded in our lives or events. I don't think I've ever said, I don't want your kids to attend X with us." Today it's a different story. And I'm okay with that story, too.

And that's the key...to KNOW the story...the history, as someone said. 

DH and I included my daughter and his kids in our ceremony (they were all young and happy to be flower girls). BM spam called DH and each one of his siblings demanding to speak to "her kids" throughout our ceremony and reception. So, yeah, I think I'd do a ceremony without them if I had to do it again. DH and I are super cool with not attending any of SK's weddings, child births, etc if that is what they want and we plan to tackle the issue when the time comes. 

Steplife is filled with double standards. Weddings being one of them.

Except Id bet the pig farm that the double standard goes against the SM in the dysfunctional toxic families, which represents many SM's on this board. They married into a situation where they are repeatedly abused, marginilized, and supposed to be OK with being excluded .

That being said , I highly doubt a SM would say this skid can come to our wedding, but this one cant. The skids have to sit at the back. Photo time only one skid can be in it cause I hate the other and its MY day so you can go to hell. Or this skid aint my family, only photos with my bios allowed. ETC ETC 

Sure there can be some real evil SM's but I think with most folks on this site wanted a good happy blended family only to be steam rolled by their DH's and/or skids.

I was 27 when I got together with my DH. We got married when I was 37. I didn't want to get married to him until his kids were out of high school. His daughter didn't like me bc I believe her loyalties were with BM. I'm a likable enough person with a zany personality. Anyway, we didn't invite his son or daughter and got married in Maui with my only attendants being my sister and her husband. We had a great time. Many years later, his son got married and we went to their wedding in Tahoe. No issues with them just his ex wife wanted to dance with him and she pushed her way into a slow dance when he was already dancing with someone else. Pictures were fine. Although his ex tried to be in one of our side of the family pics and her son(the groom) told her "mom, you gave up that right a long time ago."  She also came running across the grass when the dj called out our last name which was for the new daughter in law. The adult kids had concerns about their mom at the wedding but overall it was fine. A few years later my SD got married at a nice venue clear across the country. Again the ex wife pulled my husband out for a slow dance and I was standing beside him when she looked at me and said "I don't care if you want him to dance with me."  He didn't dance with her. He stood there like a stiff Tin man and she walked off mad. I think step life is very hard. We have all been estranged for almost 3 years. It's very sad. 

Have to suck it up the toxic abuse from skids happily, despite often doing more than the bio parent or biomum and then come wedding time stepmum is excluded along with bio kids of the subsequent marriage or the biokids (half siblings to bride or groom sd/ss) are invited along with dad.

then you are shunned and if you are invited you are put in a back corner, not allowed in any pics etc so skids can fake the 1 big happy family bs.

then when stepmum says enough and i don't want those who don't support me or my marriage at my wedding only for them to create a scene and make my wedding about them or skids who actively tried to destroy my marriage to their dad out of petty spite and boredom.

its not a double standard because what you're stating doesn't always happen. Stepparent didn't intentionally come into a blended family marriage/relationship to intentionally be spiteful to skids, alienate them and throw them out of our family/household. The vast majority want a harmonious inclusive respectful and civil household but many petty skids aren't interested in that

This stirred up all my feelings this morning!

DH and canceled our wedding. We were supposed to have it on a beach here where we live. It was going to be beautiful. However, BM wouldn't let SS come out for it. So, instead 2 months early, while visiting DH's family in KS we got married. We planned the whole thing on the drive there- Amazoned a dress, everything done from the road. All so that SS could be there. To us at the time having all 4 kids there was the most important thing. More than my family and friends. We did have DH's family, which is wonderful. My BIL walked me down the isle at the family church, and it was beautiful and special, but if we could go back- F that. We would have gone through with the wedding we planned that was what we wanted. 

I will never be invited to anything related to SS18 in his life and that's ok. I didn't do anything wrong. BM is just that horrible of a person. I only supported SS and if he can't see that, that's on him.

One thing i will also say - a lot of SMs probably are afraid to have their husband go to these weddings without them, in fear of what inappropriateness (sp?) or influence BM might have on them. It's not always about pride or being spiteful. There are SMs on here who were happily married for years with no problems from BM, then after a wedding or a grandchild or some issue, the husband becomes re-enmeshed with BM, and the SM's life was turned upside down. 

When you raise. A Stepchild. It's something you really don't have to do. You spend your time effort, money,  ect. You adjust your life for some body you don't have to.  Then the SK who could be living in a car eating dog food. With out your help. Just turns on you.  You could of been like there father didn't give two sh*t about his own kids. 
At least a SK could is thank you by having you at there wedding.  
Not have SK at yoir wedding that the bio parent thing.  Bio don't want kids screwing up there wedding.

We eloped. I didnt have all the wedding traditions. We said "lets do this" and we did it. I really wish I had had all the traditional stuff. I have never been married before and dont really see myself doing this again with anyone else.

I even said this last night that Im going to divorce him so we can have a "do over".

That being said, the general reason we did it that way was to avoid  drama and bad feelings. Absolutely no one wants to spend 30-50k on a wedding where there is one iota of bad feelings ANYWHERE.

So, on both sides, if a skid is wanting to exclude anyone with bad feelings no matter where they come from, its sort of undestandable. Same with Stepparents.

AND that being said, its rude to exclude anyone if they are being drama free plus ones. Especially if they are the spouse of a parent and especially if that parent is using marital assets to help pay for all that hoopla.

Also, just stopped by to say that i am absolutely terrified of SO's kids' weddings. He has 4 kids, 2 BMs, and both situations have the potential to be minefields. BM2 is from the same country as SO and is close with a lot of his family. Huge weddings costing $100k are kind of a thing. At the last one i went to, his cousin's parents rented out a casino. Mother of the bride changed outfits several times. Lots of processions and such. The groom's parents are expected to pay and SO has 2 boys with her. She likes the finer things. I can see her pressuring his family to pressure him to pay and participate, and i can see his parents feeling "shamed" by the community if he doesn't. 

I think you are looking at two entirely different issues. It is extremely rude to only invite half of a couple to a social event. Would they invite Uncle Jack & not Aunt June, even if everyone dislikes her? Doubtful. Even if Aunt June was a raging alcoholic, probably not. You invite both or neither. Especially given this is a celebration of the skids UNION, it is very hypocritical. Would the skid be ok with their new spouse being excluded, also very doubtful. 

It is socially acceptable to invite a couple without their children. It also makes a difference if the children are minors or adults. The parent of a minor does not have absolute control over the schedule for their children. There are reasons why not having the steps their would be acceptable, especially in high conflict situations - other parent refused visitation, other parent would make the children's lives unbearable, ceremony would be disturbed, etc. Those getting married without steps without a good reason, I would hope the parent would think enough of their child to say no.