Been a bull three times but the scenario is strange. Visited a friend in college out of state. Total stud of a dude, built, parents have money, handsome. He lived with his girlfriend, she was a ditzy blonde with huge tits. I made a comment she was hot, he showed me nudes, right on. Later in the night she was very flirty, touching my thigh under the table, giving fuck me eyes, the works. Told my friend, he asked if I was uncomfortable, I told him no I just wanted to tell him. Get back to theirs and she goes to change, he asks if I'd be down to fuck her. "Like a threesome?" "Kinda, but I just wanna watch". Tell him I'm not certain, don't want things to be weird between me and him. He just kind of "I get it" shrugged it off, she came back out a few minutes later in tiny athletic shorts and a tank top with no bra. Few more drinks, she's spilling out of her top, and laying it on heavy. He goes to the bathroom and she's all over me telling me not to worry and let it happen. So I do, start kissing, clothes come off, she's blowing me for a few minutes. Friend comes out, sits across the room in a full blown cuck chair scenario and just watched for awhile. I started fucking her and he gave some direction here and there, but just like slap her, pull her hair, etc. I can see from my peripheral he's whacking off now and I glance over at one point and he's jerking a forearm of a cock. At her request I finished on her face, then she went over to him. She just sat there, never touched him, and told him he was a "brave boy" for watching. He added his load in like 25 seconds, we all went to bed.

Very surreal experience, we have done slightly more arranged scenarios two other times, pretty much the same except the second time I fucked her ass and she told him he'll never get to have her that way