Longdistance issue regarding my girfriend and a guyfriend

Im in a long distant relationship with my girlfriend, and I just got faced with a issue regarding a mutual longtime friend.

Now a mutual friend of ours that she has previosly slept with once several years ago. (before we got involved) has moved to a city close to her and wants her to come up and celebrate halloween with her.

Should I let her go? And what happend to us if I tell her she cant? I feel like whatever I do I cant win..

I told her I was uncomfortable with the situation, and she said she could cancel her plans. I feel like nothing will happen between them, however I still fell uncomfortable with it and feel trapped by the situation.

Additional info:

I told her today that I was uncomfortable with her sleeping at another mans house that she has had sex with.
We are all 3 mutual friends and knew eachother before we got togheter.

What do you think I should do?

longdistanceissues wrote:I told her today that I was uncomfortable with her sleeping at another mans house that she has had sex with.

Sounds reasonable.