How should I respond?

[sauvignonismydrug]

I'd appreciate some advice on something that has just happened as whenever my husband and I discuss his children we usually fall out. Back story is that we've been together 8 years, married for 4. We were both previously married for 10 years to other people, I have one surviving child from my 1st marriage, he has 3, and we have one child together. My child and our child live with us, and his 3 children stay with us regularly.
So, the 3 DSC have just gone back to their mums, around 20 minutes ago. They have been here for 5 days during which time I have cooked, tidied and cleaned for them. They all received generous Christmas gifts, which they all seemed to like. The older boys in particular (17 and 14) have spent most of their time on the xbox, watching films and on tablets. In short, they have had a nice time. However, all 3 have just walked out the door without any comment to me. I don't expect thanks, but a 'bye' would be nice. Then, having forgotten something my husband popped back. I told him that they hadn't said goodbye to me or their sister, and he said he asked them if they had said goodbye, and all answered that they had. So I said not to send them back in as I didn't want to make a big deal of it. As he stormed out he commented loudly enough for me to hear 'well, you just have'.
My DSC very rarely show affection - the older 2 have never ever hugged me and the youngest always turns her head away should I try to kiss her (although she always comes for a nightime kiss along with my daughter). This has also happened before, about 6 months ago after a week long stay, so I know we will end up arguing about it. I feel gutted that I have done everything I can to make them comfortable but they don't even say goodbye? Should I just ignore this or should I discuss with husband?

Standing at the door and waving goodbye is something reserved for 'guests' surely?
A 'right, we're off now, the cars all loaded' is a far more typical reaction from a member of the family.

Saying that - the period of transition between homes is a challenge for even the most well adapted of DCs and professionals advice is to give the DCs space to interact as much, or as little, as they need to in few the hours immediately before and after 'swapping parents'.
try not to take it to heart, OP, it's probably nothing to do with you, at all, just their way of coping with an emotionally charged situation.

Thank you all for your comments, it's interesting to see people's differing perceptions of this. Maybe I am too sensitive about this but it is my expectations of 'normal' I guess that people say goodbye when they leave a home. When I leave for work in the morning, I shout out that I am leaving and then my husband and older daughter come and give me a kiss in the hallway as I leave. I certainly don't expect them to be standing like sentinels at the front door waiting for the moment of departure. And this is also what my DSc see every other weekend on a Monday morning when I leave for work before their dad takes them to school(of course I don't even try to kiss or hug them as they don't enjoy physical contact but I always say bye, see you next week to them).
To the comment that of course I knew they were leaving - well, yes I knew that was planned yesterday but standing in the doorway whilst 3 children walk in out and with belongings really isn't practical. I feel that the implication that I have deliberately stayed away from them rather than get out of the way (as I would with my own children) is an attempt to suggest I am looking to find fault.
Oh well, thank you again for your suggestions. I have decided next time to go with the 'let's say bye now so you can leave at your own pace' scenario - not because I think it's unreasonable to expect 3 children who know me well to say a goodbye but because it is the least controversial.

If they are normally only with you every other weekend then it is relevant what happens at their mother's house. Perhaps it isnt important to her (and so them) that everyone says goodbye to everyone in the house before leaving. So if they arent used to doing it then it is probably as simple as them not thinking to do it at your house rather than them choosing not to.

My dps kids will happily leave/ go to bed without saying bye or good night. He has to prompt them every time. If they are in the house before I come home I walk in and say hi to whoever is in the living room and shout a hello to anyone that's upstairs. I seldom get a hello back. If dp notices he pulls the kids up.

When the kids are leaving I'm usually in the middle of doing something so don't notice when they are all ready to go dp shouts through that he'll be back shortly and I say bye but the kids never/ rarely do. It pisses me off but I have bigger battles to fight wrt the kids.

OP it's defintely frustrating as I see it as manners to say bye when you leave anyone's house. I couldn't imagine walking out of my mums house without saying cheerio to everyone that's there (family or otherwise) I think in the land of step parenting though there are bigger fish to fry. Maybe being more proactive and initiating the greeting would help. I totally get why your frustrated though. X

OP, I don't think it's much to ask that anyone coming into or leaving the house says 'hi' and 'bye'.

My DSS does not do this and I think it's poor. I don't take it personally any more though as he does it to his grandmother and others, too.

But that doesn't excuse it. DH prompts him but not consistently. I'm not sure what he expects the message to be to DSS - that basic manners are not important?

As others have said, though, is this the battle you want to pick? I just keep saying hello, goodbye etc myself and try to tune out any lack of response.