Adultery?

I have written and rewritten this entry at least five times.

My wife wants to “be more than friends” with my best friend.

Let me start by saying I have allowed them to sleep together in the past, but she assured me there was no more to it than that. That was three years ago. Apparently, for my friend who is married himself (his wife has a boyfriend), he did not let go.

They have gotten closer and closer and I have allowed it, stupidly. Now they want more.

I said no.

This is not a good time in my relationship or life and I don’t know if it ever will be.

What should I do?