It sounds like he is doing a really good job of hiding his relapse from people. Actually, my experience is that the louder they boast about being sober, the less likely it is that they really are. It's amazing how many people around them are tricked by their words, but those who take a close look at their behaviors know better. His behavior is not that of a sober man.
Hugs to you. It's sad how much we hurt for our babies, huh?