Very nearly had the chance to do this recently. My current girlfriend is quite into the whole girl girl boy thing, and arranged a threesome with her new friend. This other girl had quite a big set, but my girlfriend has got smaller ones. When it came to the night, wrapping their breasts around me was going to be one of their plans. But the friend got really shy about something and they went outside to talk. I would have gone with them, but prior to that, they handcuffed me to the bed. By the time they got back, it was very late and the friend didn't really feel like it afterwards. It was a big tease, yes, but that's the closest i've ever come to that.