"Should I Tell My Sister I Slept With Her Fiancee?" - Lady Seeks Help

During my wild days in the university nine years ago I had a brief fling with a guy I met through a friend. We had séx a few times and saw each other for about a month before we lost touch.

Fast forward eight years later; my immediate younger sister introduced this same guy to me as her boyfriend. I was hoping they would break up so he wouldn't be an issue between my sister and I but that didn't happen.

A year later, they are getting married. Their wedding is actually this Saturday December 15th. There's serious friction between the guy and I as we can't even look at each other or talk directly to each other.

I have been avoiding him since he hooked up with my sister but now that they are about to be married, I'm stuck.
Should I tell my sister what happened between us or leave things the way they are? Does she have a right to know?
I'm confused. Pls help!!!
Follow BrickClicks on twitter for instant update Follow @BrickClicks