Oh dear - christmas is hard in any family, and in step families it is almost impossible! Have your OH and his ex actualyl sat down together and discussed this? I would be saying (very, very clearly) that this is what DSS wants. Has your DSS told his mum that he would like to spend it with you? that might help too, although go easy if this will put him in a difficult position, I think it depends on the child.
We are having a similar issue this year with my DSD's mother - she is demanding Xmas although she had her last year, we have already booked to go and stay with my family. We have tried to be as reasonable as possible, but DH is putting his foot down. I think it's a bit easier for us though because DSD is here full time. The problem is - it means that DSD has her mum wingeing at her constantly about it - I have lost count of the times that I have said to DSD to let mummy and daddy discuss it between themselves when mummy has yet again upset her by telling her that she will be lonely at christmas without her and isn't daddy horrible - considering that she is only 7 and had a terrible time last year as 'mummy didn't buy a tree' grrrrrrrrrrr sorry to turn this into a rant!
Basically - I feel for you - it's not easy! You have to be guided by what the child wants, ultimately. Good luck!
Thanks for the responses. allnew I think you are right, DSS has already started saying now he really doesnt mind where he goes and seems scared to say otherwise as he is obviously aware that it will cause conflict and like DH, he tends to avoid such situations.
DH is going to talk to his ex again although he's not confident of getting anywhere. He doesn't want to force them all down the court route when she pretty much keeps to the every other weekend agreement, it is just Christmas that is the sticking point.
It is just hard to watch the situation, trying to support but not to interfere.
Oh dear how awful, his mother is of the ilk that clearly thinks she is the most important parent and owns the child accordingly. Very difficult to deal with. I guess all your DO can do is to go with what DSS wants and try to follow through with that. Thing is I don't know what she's like. Is she likely to show her anger with DSS and stress him? DH's ex does thus, it's a very effective control mechanism as they back down on their wants to avoid making her angry. Is his mother likely to do this?
The only way of avoiding tension is to do things her way; which isn't what your DSS wants - so if your DH avoids tension, he is letting his DS down.
I would suggest a straight forward approach "This is what DS wants, I'll be there to pick him up at X time"
It's up to her if she chooses to cause a scene - your DH cannot control her actions.
I've recently done this once or twice now my DD is about the same age and have stood up to her Dad - she has been very grateful, and all ex's bluster is just that, he has never followed through on his threats.
DH and his ex split around 6-7 years ago when she left him for her new partner. She took DSS to live with her 2 hours away and it was agreed that DH would have him every other weekend, occasional weeks in school holidays and that they would alternate Christmas.
The alternating Christmas bit has never happened in the almost 5 years I have been with DH. DSS has always remained with his mum for Xmas and we have had him the following or previous weekend. Although not happy with this, DH has never pushed as DSS used to say that he wanted to spend Christmas in his own house.
However, this year, DSS has said quite early on that he would like to come to us at Christmas. He is now 12 and has been made to spend the last 2 Xmases with his mother's partner's family who live even further away from them than we do. He kept asking DH to speak to his mother about it so we could get this year agreed. So DH trying to be reasonable suggested that DSS wake up in his own house, open presents there and then either we collect him mid-late morning or they drop him here on way to her partner's parents or we meet up with them on their way. DSS is with us for the rest of Xmas Day and then they collect him or we meet up with then at whatever time they leave his parents on Boxing Day. So we have tried to fit around the plans they have already made as much as possible.
DH's ex has gone mad saying she can't spend Xmas without her DS. DH has pointed out that he has been spending every Xmas without his DS. He is very upset about it but doesn't know what he can do as his ex is absolutely refusing for DSS to come to us at Xmas. She has said he can come on 27th onwards, we are both back at work then. DSS is also upset and I don't know what to say or do. DH doesn't want to cause tension with his ex but does not think he is being unreasonable.