I slept with the groomsman how to handle it?

Anonymous
my wedding is in two weeks, the groomsman is my fiance best friend, he had to come to my place for something (can't mention it) we talked then kissed and it escalated to having sex
now I regret it a lot and I can't deal with the feelings of shame
do I need to tell my fiance to put my mind and heart at ease or should I keep it a secret and suffer?
Updates
3 mo
it got more complicated
the groomsman wants to propose
I slept with the groomsman how to handle it?
34 Opinion