Oh my God! My husband's best friend fucks me while he's in the shower!

I'm going to take a shower and my husband is bathing while I wait for him. I'm getting ready in front of the mirror, but to my surprise, his best friend comes in and tells me to be quiet. Even though I got nervous, it turned me on, so I couldn't resist fucking him hard behind his back. The bad thing is that we got caught and I ran away.