<human>: Can you summarize the given text in a few sentences?

We're not official, but we've been dating pretty exclusively for the past few months and the fact that some of his best friends are female didn't bother me until recently. 

He knows a lot of them through a school club that also vacations together bi-annually. He's talked about these trips, but never in detail. He'd just mention that everyone gets smashed and parties. I never thought anything more about it until one of his roommates mentioned that they basically have orgies. 

The conversation got shutdown pretty quickly after that. I could tell it made him uncomfortable when his roommate brought it up, but that just makes me more curious. Am I out of place to ask about it? Is it wrong of me to be bothered by it? I'm relatively new to relationships, so I'm not really sure what's standard.
<bot>: Kind-of-boyfriend goes on bi-annual trips with close female friends from a school club where orgies have taken place. Do I have a right to ask about it and/or feel jealous?