The only thing you can do is get a good court order on visitation, child Support, what exters are payed. Ie medical.  And stick to that CO.  No playing games with BM. No changing CO on the fly. 

She may do anything to screw up your relationship with your SO, buy giving you the SK every weekend. Making you pay for everything ect.  Set your game Pland  and stick to it.  

She already trying to screw you up by saying you have to Wate  a year. ???   Be careful.  Also set up now. What going to be paid for birthdays, Christmas,  and the big money items, cars, car insurance, college, wedding, money for there homes, and GK,   Setting up your funding of 401 for you and your SO.  Get this in some form or writing so history does not get rewritten latter on

BM is indeed a lunatic.  She just doesn't want him to move on.  It's on Page 1 of the Psycho Ex manual.

Order a copy of https://www.amazon.com/Say-Goodbye-Crazy-Restore-Sanity/dp/1514683814

Do you have children of your own?

I think the big ticket question here is this. ---- Are you willing to deal with this woman for the rest of your life? The kids will outlive you, meaning that this woman will forever be in your face until you die.

If the answer to that is yes, good on you, your man has a golden weewee. The best you could do is probably... not care.

The ex-wife is adament that I not have any contact with them, that I'm going to cause them stress and harm. She's demanding that my partner wait a year before I'm a part of their lives. This is completely ridiculous and we're not granting any of her wishes. 

She should trust him enough to have sound judgement when it comes to their kids. Either way she doesn't get to dictate what he does or doesn't do with them during his time. She doesn't get to demand that he do a damn thing, and if he bends every time she does, it will set the tone to her running his life forever.

Set the precedent now that he appreciates her input and concern about their kids, however he is not complying to her demands as he knows his kids are safe and in good hands. Boundaries have to be created and maintained and always have to be consistent. It may be tough at first but you'll thank yourself for it in the long run.

Why do these people divorce if they want control over their kids and “ex” partner?Ugh I don’t miss my steplife and so glad we are done. My exes ex was very controlling but in a passive aggressive  “I’m just going to stop by your house and hang out with my kids there and call every night to talk to my kids even when you’re on vacation.” Kind of way. So glad that’s over. One way or another the exes are going to be drama and a mess and your partner is usually the reason behind it all. He needs to handle this better for everyone’s sake.

Here's the thing.  The ex-wife isn't in charge of YOUR relationship UNLESS your SO allows it.  You can ignore her.  I'm afraid, though, that it doesn't bode well for you that he appears to have no backbone in dealing with her.  Who agrees to stay for 7 weeks after the divorce is final?  And waiting a month after the divorce to even tell the kids?  It sounds like she is used to telling him what to do and having him meekly comply.  He needs to set and maintain boundaries.  If he doesn't, you are in for a rough time.

She does not have the right to dictate what happens in her Exhusband's home.. and does not have the right to dictate his relationships period.  He has the right to have his kids around whomever he wants.. he could have a new girl in his house every week.  ZERO say on the EX side. 

He needs to shut this down with her NOW.  She has neither the right nor the standing to make these requests.

Barring that you are a harm to the kids in a litteral sense.. abusing them or doing illegal acts in front of them?  Nope.. sorry woman.  That divorce decree means you have zero interest in your exhusband's life.. and the court gave him visitation.. so he gets to decide how that works.. and who his kids are around.

Do not let her have this power.

Control of the X is not an easy thing to implement. What is easy to implement is that you nor your SO allow her any control over you, your relationship, or his relationship with his children. BM gets zero say over what he does with his kids during his time with them including who he chooses to include in that time.

She needs to be told to STFU and keep her nose on her side of the divorce decree/visitation CO.  You and your SO need to focus on your own connection and being equity life partners and a team against BM and her crap.

You need to educate yourself on personality disorders and how to deal with them.  You need to understand what IS HEALTHY and what is not.  I can guarantee you that so far she is unhealthy and your gut is screaming about it.  

Books and websites that will help you understand and strengthen your fortitude are:  shrink4crazy.com and lovefraud.com.  Websites for Divorce Poison and Dr. George Simon.  Boundaries book by Cloud and Townsend.  

All of these were my resources thru the dark and dreary days of daily step life and I always recommend them.  

If your man can not put his ex and skid in their proper place in his life and forces expectations on you that make you  subside on shit sandwiches, he is not the man for you.  You deserve a man who knows how to keep things straight.  

Pas aggressors shouldn’t have custody or be around their own kids because they have no intentions of ever producing and raising productive members of society but yet they need to meet the new gf and approve of her and lay ridiculous conditions etc??

my husband was already divorced for 4 years plus when we met and exwife with the holy golden uterus who bragged how in demand she was and could snap any man in an instant and even had her ex highschool sweetheart dump his wife to marry her 1 week after the divorce and they had been cheating on their spouses even before they were in the process of divorcing, had gone whingey bitch to her friends at hubbies work (aka spy whores), she ranted to hubbys elder sister that i was a Caucasian christian whore and she had to protect her 2 daughters from me (she had kidnapped them a year prior and saw an angle to spin it her way). 

Sd’s found out the lies and started questioning her and now she is a born again religious person and they are gullible enough to believe her

exwife even demanded mid last year that i must be present at all meets with their 2 daughters and hubby. I had a 1.5 & 2.5 yr old at that point and after 3 meets where sd’s sat in silence unless they were ranting about bio mum this and stepdad that, i told hubby she can go eff herself and his daughters if they think i will inconvenience myself and waste my and my toddlers quality time together for these useless effwits..

now exwife bans the 23.5 yr old from meering daddy along with 14.5 yr old...hubby needs to ask sd23.5 permission to see the younger daughter... now when there is a long weekend or holiday time hubby is jumping to spend time with me and our 2 kids because skids and exwife are all batshit crazy dumbass leeches of society

i will never waste my time and have firmly told hubby i willl not attend any family events his little spy bitches will be at that hubby volunteers picking up who are disrespectful and do not respect our privacy and boundaries 

You are absolutely none of BM's business and she has NO control over you or how much her kids see you.   I had exactly the same issue as you, when I moved in with DH, NPD BM was very controlling, and he would think he had to do her bidding otherwise she'd retaliate by withholding the SDs from him.  Well gradually, over about 5 yrs and partly as a result of my coaching, DH realised he didn't have to put up with her shit, and eventually got to the point where from listening to her 20 minute rants on the phone, he'd put the phone down as soon as she raised her voice. 

The only way she can control him is if he chooses to allow it.

Currently in the throes of separating from my partner, as he has chosen to allow his ex to dictate the terms of his life. I hope it is fixable in your case. Unfortunately, it was not in mine. 

His ex thinks it’s OK to ask questions about things related to when they see me and what we do.

She thinks its OK because he hasn't shut that down. He can do so politely. I'm sure he knows how to word things so that he doesn't come across as an @sshole.

I wish he was more assertive with her when he responds to her epic long email rants but he is generally nice because his biggest fear is that she can retaliate in someway and maybe take him to court.

He has nothing to fear as you stated the courts will not entertain BM bullshit because he has the kids around his girlfriend. The more he bends and responds to those ridiculous emails the more of your life she will consume. He's acting on fear when he doesn't need to be. If she types another one of her stupid emails he can send her a one sentence response that again "he appreciates her input but the kids are safe and sound and she has NOTHING to worry about" and leave it at that. Stop entertaining her.