I used to do that, and she'd hate it. It was maybe once a month, but since we never saw each other, we'd end up bullshitting until 1:00-3:00 sometimes. Then it got to the point that if I'd go golfing with friends on a Sunday she'd get upset (she doesn't golf). Then it was if I went to lunch with friends, she'd get upset. Last night, I was working until almost 1:00. Guess what... she got upset.
Are you getting fucked up while you're out? She's probably worried about you making it home ok. Also, if you're out with single friends getting wasted, she might be worried that your judgment may lapse. It would only be natural. I'd address it and figure out what's important to you. Just respect each other and follow through on what you decide.