The conclusion that I came too when  SD was doing this is that it was to see who could "win" and be the one in control of daddy. Was he given way too much control/say in things? SD definitely was from the time that she was very young and I think it caused issues. 

My advice to your DH would be to gave a talk with him that he needs to do adult things sometimes too and it doesnt mean he doesnt love him, and so on. If he doesnt stop then a "knock it off" without showing any guilt is probably needed. Hes a little old to be that upset about it imo. And I'm right there with you in getting driven up the wall by the neediness. 

I am sure it is right what  Jcksjj said, ie the kid wants to "win" his father's attention.  My 2 SDs were exactly like this, especially the older one.  If occasionally we would go and see one of my DDs, war would break out - I remember SD24 saying once "it's always about THEM" ie my daughters - when the truth was that we would see them 2 or 3 times a year because they live a long way away.  

They finally stopped this when they stopped coming round EOW, which was in their late teens.  It may take a long time for your SS to stop - he may never do so - so disengagement is a good option, but if you are like me you will still feel resentful at being sidelined for an overly clinging kid.   In my experience these type of kids are not good at developing their own circle of friends, and tend to rely on mummy and daddy for their social life.  My two SDs still do this with NPD BM,  go on holiday with her and spend weekends with her and they are 24 and 22.  

Does BM know of this issue? I could bet money that she does, and she feeds this kid full ideas to irritate you, as she stopped her life, she wants you and daddy to do the same! 

Ok so by 12 this behaviour should definitely  have stopped. It's just weird.

Cutting your vacation short is unbelievable and I'm surprised you put up with that sort of crap. I'm literally speechless at the position you're in.

Your DH must be allowing this behaviour and is even giving in to this behaviour by cutting his vacation short and most probably allowing ss to sit/walk next to him rather than telling him he's a bit old for all that now. Sorry but I think your problem lies with your DH,  he needs to step up and stop this.

My DH would not have put up with that from SS for 10 minutes. 

As usual, you have a DH problem. 

Unless someone was dying, if my DH ever decided to cut our holiday short to molly coddle my SS's, 2 things would happen.  1. He'd be leaving without me, and I'd help myself to anything I felt like, courtesy of his card. 2. It would be the last holiday we would take together until DH got his priorities straight.

As irritating as your SS is, your DH is to blame because he lets his kid get away with it. 

This behavior at 12 years old? Yeah, that’s NOT normal at all. 

Your DH is making a conscious decision to contribute to a codependent situation. He’s aiding his ex in keeping their son emotionally stunted. He has got to knock it off and be the change for the betterment of his child’s emotional well-being. 

I mean, my god, a 12 year old boy throwing crying fits about how dad spends his well-deserved free time? No no no no. Perhaps he should get his child into some therapy. 

What age can I expect some relief??? When will SS be more interested in friends than hanging all over daddy? What age should SS not throw a temper Tantrum if he doesn’t get to see daddy for a week??? 

This behavior right here is your H's and BM doing. Your H is enabling this! He's not parenting, creating boundaries, and disciplining his son. You both should be able to go on vacation without the tantrum and should SS do so your H still needs to stand firm. You may never get any relief, no matter how old he is his son will "always' be there in some needy capacity. Your H has to put in the work to have his son more dependent on entertaining himself instead of being up in his @ss all the time. Your problem is with H not SS. If your H doesn't make changes you will never have relief and will continue in a marriage with a SS that never goes away.

He's a boy -- unless he has a true emotional issue, don't you think his peers will soon cure him of this behavior? Peers will identify this behavior as not OK and send the message to SS if it keeps up.

I stopped sucking my thumb because I was old enough to start going to sleepovers. I was ashamed! Shame's a good motivator!

Is this kid spending enough time with boys his age? Kids without siblings don't have anyone at home to provide that shame effect (and it's not OK for adults to shame kids for anything anymore). Maybe your SS has no idea other kids don't act like that to get what they want from parents. It would be a shame for other kids to label him because of it. Once he's marked by other kids...ugh...that's the kind of stuff that can follow you through school.

Maybe that's how you paint it to his dad, especially if SS is entering a new school in fall: "Honey, SS's going to middle school this fall. I don't want him to struggle socially. If he's this upset when you leave and he's crying like this, he's not confident enough for middle school. The other kids will sniff that out and I don't want him to become a target."

Teenage years are just so much easier for kids who don't stick out too much for socially-unacceptable behavior. Why wouldn't he want to give his kid an easier time?

You have a long way to go, if it ever even stops.

My SD16 and SD11 show zero signs of letting up on this behavior. They can do nothing for themselves. They have BM, DH and MIL practically trying to change their diapers and put the lids back on their sippy cups. Freakin idiots.

SD16 cant and won't drive....she goes to school when she wants to and when she doesn't BM runs her to dr for some bull shit diagnosis...which is now regulary 50% of the last 4 months of school. These kids have no friends, no social life, nothing......but this is how they were raised I guess.

He is doing this because daddy gets something out of it and enables it.  This is a mutual admiration society where the codependent bullshit gives each of them something they want.

What that is... is probably obvious to you since  you are in the thick of the nauseating crap.

I would give DH absolute clarity that YOU get him for your annual vacation and that there will be NO whiny Skid crap that interferes with your vacation in any way.   No interference before the vacation, during the vacation, or after the vacation. Nothing that jeopardizes the excitement leading up to the vacation, nothing the interferes with the enjoyment of the vacation when it is happening, and nothing that tarnishes the memories of the vacation when it is over.

Daddy needs to man up and end this needy kid crap immediately and permanently.  No more clingy crap, no more baby crap and no more interference in the adult relationship that you have with your DH.  This is a 12yo not a 2yo.  There should be zero tolerance for anything less than appropriate behavior expected of a 12yo.

Period!

This kind of behavior is not exclusive to step families. You just see it more clearly becuase you are essentially an outsider.

Nor will this behavior necessarily stop. My ex made my life miserable, while we were together, catering to our kids at my expense. Their enmeshment destroyed them and there wasn't a thing I could do about it, except to have taken the children and left him, which I failed to do and which he'd have fought iand likely won in any case. I did finally get out but my kids did not. Their father died 10 years ago and they still proudly display huge ugly tatoos on their forearms that read, "I love you Daddy." Bofh of them, adult women. It's nauseating. And please note, I say this of my own flesh and blood. They've never gotten over their enmeshment.

I thiink what I'm saying is, if you want peace, you're going to have to get out of Dodge. This is never going to stop.