Re: The hotwife fantasy
Bringing other people into a monogamous relationship is fraught with dangers, to be sure.
Swinging was mentioned. Divorce rates tossed around. I've seen studies suggesting swingers divorce less often than monogamous couples. Personally I doubt there is any difference.
As it happens my wife is bisexual, and really does appreciate/need a woman in her life on occasion to feel whole. She certainly needs to know it is an option. For several years we did participate in the lifestyle so she could have an easier time finding girlfriends.
Jealousies do need to be taken into account. The worst thing to do is be Politically Correct and say someone should not be jealous of this or that and blithely go on and ignore possible problems. You must accept people do get jealous, no matter how much they may claim they are so modern and won't.
A side note: Every couple we knew who was swinging last century is no longer a couple, except my wife and I. I suspect that is because they were doing it to find something they couldn't get from their Significant Other in another person of the same sex as their Significant Other. My wife and I were involved so she could get something I just simply could not provide for her. She didn't care about the guys at all.
We did have ground rules specifically to deal with jealousy. Neither of us are jealous people, but we still rigorously kept to our rules to make sure there was never any issue at all. We did everything together, always.
But overall I think swinging is bad for a relationship. Most people place too much emphasis on sex as some sort of supreme intimacy. Sex is just sex. It's a fun exercise. But because most people whip it up into some sort of super big deal swinging becomes much too dangerous.
The biggest problems are intimacy issues; showing love for someone other than a spouse, or excluding a spouse. Yes, hiding anything from a spouse is a death knell to a marriage.