Nope. He just forgot.
AND . . . the two of them went on a "field trip" into the city to have lunch w/ me on Wednesday, and neither one of them, apparently, thought about making a side trip to get a "make up" gift.
Because on NYEve, when we sat down to open the late-arriving presents, there still wasn't one from my son.
My husband said to me the next day, "we'll make it up to you."
So, I'm mad. And given that I've said something to my son already, I don't think there's anything else to be said right now.
I was talking to my aunt on the phone and told her about the no-gift thing, and my son in the next room overheard. And said, "I love you, Mom." So, I have that, even if I don't have a present.