My guy friend. I used to jack off with him about once a week when we were around 14 watching porn on VHS. Not sure how we started doing it though.
I think one of us just went for it and the other one followed. At first we hid our dicks but eventually stopped caring and just did it out in the open in front of each other.
We stopped doing it for a long time and then one day when we were like 20 we watched a porn and jacked off again for old times sake. That was the last time.