Iʻm gay, and we have worked through some of these questions earlier, perhaps, than hetero society. When you have been labeled a sexual outlaw and assured that you are going to burn in hell for eternity, there is a tendency to say “what the fuck” and do whatever it is that you feel like doing.
In any event, your article made me think. Of my eleven closest male friends—some of whom I have known for 20 years or longer, I have had some type of sexual contact with nine of them. I have enjoyed a very close and longstanding romantic relationship with one of them; two others briefly contemplated something more serious, and the other six understood from the get-go that it was just something we were doing for mutual pleasure. They all remain good friends today and I continue to engage in fairly frequent sexual activity with four of them.
So .., yes, absolutely, sex with friends can work – and, indeed, work very well for all concerned.