Husband goes out to bars and then complains that he is tired

This is driving me crazy. My husband lost his job before the baby was born and I am on leave. He has always had trouble getting to sleep. He has been staying up until our baby wakes up at about 1am and feeds and changes him. But what is getting me upset is that he is going out to bars afterwards (once or twice a week) and coming to bed around 4am and ends up waking the baby. Then my husband sleeps until 1pm, and tells me he is tired. I am upset cause he is tired from going out (which is a choice) not from taking care of the baby. I keep telling him that he should try to sleep when the baby is sleeping, as of 8pm, but he tells me he can't. He responds by telling me that it's only for a few hours, so what's the big deal.

*our baby doesn't nap very long during the day*.

Am I overreacting?