Do you and your partner share the same drinking habits? Are you cool with how much the other drinks? We recently found out that my FI's one friend's girlfriend is such a major alcoholic that she has liver damage that may kill her. We always said to ourselves that she was an alcoholic, but we had no idea the extent...she's been hospitalized three times this year.
Since I met FI, he eventually would show that he was annoyed when I was even buzzed. I concluded that this mostly occurs when I'm drinking and he's not...and more often than not these days he doesn't feel like drinking. So if I drink he will often "caution" me about drinking, etc. and it annoys me. As long as I'm not driving, I don't see why he should care if I drink a few even if he doesn't. Yes, I tend to get hangovers, but damnit, that's my right! But, he's annoyed nonetheless. We mostly only have drinks when we're out to dinner so we are mutually buzzing, but on those times when I drink and he doesn't it's just a bummer for me...not even worth it.
ETA: self-disclosure: FI is out at a car show and dinner with his bro - so I am on my third Sam Adams Summer Ale.