Sex with a friend is a minefield
Sex with a friend is a minefield of maybes, and a good majority of the time, you don’t make it to the other side without losing a limb. That’s why, in my humble opinion, sex with a stranger beats sex with a friend. There’s no baggage. No white elephant in the room. It’s far easier to let it all hang out if you know you may very well not see your sex partner again. With your friend, you have no choice. It’s your friend.
You know how much the friendship’s worth to you, and what you stand to lose by letting sex get involved. Personally, I think it’s a gamble that can pay the hugest possible dividends. Just remember that in the end, most gamblers lose.