Starting to see cracks?

WH acting strange this week - don't know what to make of it.

Have basically ignored him all week since overhearing him make snide remarks about me to grad student Monday night. He "rushed home" Tuesday by 8:20 pm to have dinner with family -- and was ticked that we'd eaten an hour earlier (never called to say when he'd be home). He also skipped a social function Wednesday night and was home by 9 pm (he never skips!). Needed his help to run kids last night @ 5:30, so he headed back to work at 9. When I asked him what he needed to work on since he doesn't have class this morning, he rattled off several things in minute detail - which meant he was really going back to spend time with OW. He was back by 11 (early!) and quickly proceeded to get drunk, which is VERY out of character for him.

This morning he was seeking me out to discuss kids and bills and tell me his plans for this evening. Again, out of character.

Would like to know what's rattling around in that mid-life crisis head of his.

Any ideas?