My H's birthday was in the middle of his anger phase and he took it pretty badly (as he did all other family celebrations). It reminded him of his aging and all the MLC stuff, he really did not want to celebrate it and got really stressed by the end of the day.
May I suggest planning a few circut breakers in case your H feels similar, as well as being tired from his trip? A couple of happy movies that can be chucked on, ideas that may give him a bit of time out, or that you can do if needed. Just suggesting low expectations, which you obviously have, but if he loops out it may just be a hard day for him and not about you.
