I wouldn't say anything. I mean, has he ever drank to the point of acting the fool at family gatherings? My mom is a drunk. I didn't drink at Thanksgiving because I don't like feeling drunk and because of my meds. If someone was all like, "Oh, good job not drinking!" I'd be like, "Thanks?"

In fact, I'm not drinking this Christmas either because I've been sick, again don't like feeling drunk, and because of my meds. I feel bad for my liver as is!

It's up to you though.

But I personally wouldn't say anything.