Pleasing A Gay Friend (M/F Converting Gay Men, Anal, Trickery)

He's huge. My gay friend and my rear are going to meet, fall in love and have a twisted one night affair. Or, at least, that's what I hoped. Right now, he's soft... I stare at it. What I can do? What would turn a gay man on? My fingers stray to my rear. Seriously, the things we do to please our friends.