Tex
My wife and I always loved to do this when we were first together. She would tell me about her last BF who had 11 inches and it heated up our sex tremendously. He was still on campus and I started seeing him in the showers at the gym once in awhile and he was really, really huge.
It added a tremendous charge to our lovemaking, like a super-aphrodisiac effect. It boosted my confidence and intensified my love for her that she chose me over him, but I was fascinated by hearing about what it was like.
I asked her to have him join us sometime. She said she wasn't sure she wanted to. I pressed it but not too hard. After awhile we went out to a movie with him and then had him come over to talk. I couldn't stand what a knob he was, had such a deadly dull, nerdy personality that it repulsed me and I couldn't imagine him with us sexually. Just no way. So we dropped the idea.
But a couple years later we did find the right guy just by chance and had a ball, literally, with him over the course of a year. We got together maybe five or six weekends--he lived 250 miles away. It was another 15 years after that that we found another hot hung dude who joined us once in awhile, this time over a period of about 3 years.
It was the hottest, funnest sex I ever had, we were all respectful of one another. I was surprised how bisexual I was able to be, hadn't anticipated anything but seeing and maybe holding his cock. I ended up doing a lot of sucking and we all kissed passionately. The memories are terrific. We often wished we could find someone who would be with us in between those two sexual friendships, but it's hard to find someone who is compatible with both. The fear of disease was considerable, but we wanted the experience badly enough and felt safe enough with these particular two partners to take the chance, with precautions of course. (Especially the second one--the first one was back in 1980 before HIV.)
We just recently heard from the first friend. Hadn't heard from him in about 19 years. Wondered if he had gone off and gotten AIDS. Found out he had a lover he had settled down with and been with for almost 20 years. The lover did get AIDS and died. How he avoided it, I don't know. But it goes to show that the danger is real.
I hate to add to all the negativity, all these people here so un-fun about sex. I share this with you NOT to discourage you but to just say be careful, use condoms, spermicidal creams, keep fluid contact to a minimum.
BUT... I disagree with all the warnings about emotional tragedy. It could happen, but it could be great, too, and problem-free, like it was for us. We both and both our lovers have NO regrets about having experimented and had the wonderful erotic experiences we had.