<human>: My girlfriend and I have an 8 year gap that is usually not a problem, but I don't know if I am being unreasonable when it comes to hanging out with her older brothers. 

Whenever she wants them to come over to our place or she wants to hang out with them I usually try to opt out and she resents me for that. Don't get me wrong, they are good people; I honestly just don't have anything in common with them. I understand that it's her family and that a day of hanging out with them won't kill me, but they're very heavy drinkers and my girlfriend drinks a lot when she's with them too and I personally don't like it when people get to that point. I used to do that when I was in my early 20s and now I find it unhealthy as I am also trying to lose a few pounds for a trip my girlfriend and I are taking in a few weeks. 

I love my girlfriend and she's always down to hang out my brother [28M] and my parents [48F and 49M], and I don't know how I would feel if she were to avoid hanging out with them. Her brothers have been aggressive in the past and they like to talk shit to each other when they're drunk and start fights. Whenever her whole family gets together though I am always there and I don't have any problem with hanging out with her sister [36F] and her husband who also like to drink but it's way more relaxed. 

So, am I wrong? What should I do? Any help/suggestion will be appreciated.

Give me a shortened version of the text
<bot>: I don't like hanging out with my girlfriend's older brothers because we don't have much in common. Am I being a jerk?