Joe,
I'm glad you didn't listen to the majority of the advice you're getting here. Guys telling you to jump at the opportunity is just terrible advice. A marriage is a special bond, but can be broken pretty quickly if someone is cheating, which would be you had you fooled around with this "friend". The one doing the cheating can't comprehend how devastating that is to the ones he "loves" which is why he starts thinking with his dick. I witnessed it with my own parents. Destroys relationships, marriages, families, and worse, spirits. The benefit is never worth the cost.