isn't this exact same topic of discussion already lying around somewhere........

IMHO...... If you can't trust her, you might as well let her go. Insecurities kill relationships...... No one wants to be accusede or interrogated each time they participate in something without the significant other. Unless it was decided mutually, there's no need to be with your bf/gf/wifey/hubby or whatever 24/7. Give us us free............ You don't get into relationships to become a slave. True enough that it isn't cool to always doing something alone, that would be neglect and grounds for dismissal; but a healthy relationship will support each of the participants wants and needs without hardship or discomforts.

Let her go, trust her. Don't act suspicious and just maybe she'll let you join the next time she decides to bump couchies with her friends..........

J/K Seriously let her go and be cool about it. You may reap the rewards of the party girl on a mission once you get off work.