Husband unhappy on the anniversary of his dog death

My husbands dog died 3 years (today is another anniversary) ago it was the most distraught I've ever seen him. I was there for him and still am. Today he didn't mention anything about it (I kinda forgot) we went out, walked our other dogs around the park, did some shopping, had sex, laughed, made out here and there awesome day overall. When we got home 8pm he told me it was his dogs anniversary and he wasn't going to have a good night so don't piss him off. Now the tone of his voice completely changed to this soft whiny baby voice, walking around slow like a zombie,ect. My husband has a drinking issue (which I usually complain about when he's had too much) and he finished 3 beers in under an hr and is still drinking...will most likely drink until he's sick and he knows I won't bitch tonight bc of his dogs anniversary. 
It honestly makes me mad bc he's using his dogs death to his best advantage and he hasn't said ANYTHING about his dog all day.