As a new person to this site, I am pleased to see that several people have responded to my original post on this topic! Hey, rickzv, greek dude, bigboy9239, kevman, iamhard89, dickman45885, and hockeyfan86, we seem to have something in common.
In light on the following comments from collegedude1 and mister 1973, I guess I'll elaborate a bit more.
Collegedude1: "I'm sorry, but I don't get it. You never "pushed" the issue? Your best friend was fucking your wife! If you wanted to watch, why did you need their permission?"
Mister 1973: "dont understand how a bi man doesnt join in to see his best friend fuck his wife, and i understand it wasnt a one time thing."
At the time, my wife and I had on open marriage. While she was loving and fucking our best friend, I was having my own relationships. Those relationships centered mostly around making up for a lifetime of never acting out the gay side of my bi nature. I loved my wife and my friend, and I totally got off on them having their relationship becoming sexual. It did not feel like it was my place to necessarily dictate that it had to be a threesome, especially since he is straight, even though I obviously would have been very happy to have things go in that direction.
My friend knew that if at any time I had had objections to their relationship, my wife would have stopped having sex with him. It was a big turn-on to know, although it was not verbalized directly, how much my friend appreciated my willingness to let him fuck my wife, the woman he craved so much more than any of the many other women he had known and fucked. I was reluctant to push a threesome because, from a strictly selfish point of view, I was already getting so much emotional satisfaction out of their relationship as it was, and I did not want to jeopardize all that.
For me, sharing my wife with my best friend made me feel close to him in a totally trusting, intimate, blood-brother kind of way that satisfied longings dating from my early childhood. Also, as I have said, their relationship was intensely arousing to me, even in the absence of my own direct participation or observation of their sex.
Back then sex with my wife was incredibly enhanced by the knowledge that my friend had been fucking her and blasting his cum deep inside her earlier in the day. Another really hot aspect of the whole thing resulted from the fact that my friend would occasionally cum prematurely when he was with my wife. Now, this guy was reported to really know how to use the great equipment that he had and to be able to sustain his sexual performance for very extended periods, but sometimes with my wife he just could not hold back. She would end up a bit frustrated by not having that final crushing orgasm she was counting on. When she got home on such occasions, she would be super horny and would look to me to finish the job, so to speak. It was a huge turn-on to realize how uncontrollably aroused my friend had been while fucking my wife, and I got off amazingly strongly knowing that I was a direct extension of, and for my wife, a culmination of, their earlier super-heated sexual encounter.
Yes, in retrospect, I do regret that I had not pushed for a threesome. As I have said, I would love to have forever emblazened in my memory the actual sight of their gorgeous naked bodies together and the sight of my friend's huge cock fucking the cunt I love. But even without that whole added dimension, my best friend loving my wife and fucking her over and over and over again was just a fantastic experience. Somehow in retrospect it was even better than the many other experiences that my wife and I have had with actual hot threesomes involving various straight and bi men. Go figure. | 
