short term gratification followed by long term misery. some guy will always have a bigger cock. I have never seen an open marriage, remain open and go full term. sooner or later, it's divorce or stop swinging.
I question this. Not questioning whether it's true (you did specify merely that you haven't personally seen it), I question the conclusion.
Just because people stop swinging after a while doesn't mean swinging is bad. They could stop swinging for a ton of reasons. And divorce doesn't say much, either, considering so many people, swingers and otherwise, get divorced.
I have an open relationship with my husband, and it's a ton of fun. But it's just that... fun. Not every "game" of different sorts is equally fun every time. Take sports, for instance. People play sports for fun, but sometimes, there's just a bad game, and it's pure frustration. Does that mean the game is worthless? No.
Same thing with swinging. If it's just a game to you, then even occasional sour experiences are all good.
And not everyone gets jealous, either. We had this three-way with a 33 year old woman (my husband and I are 23/22, respectively). That woman was experienced. She ended up giving him a blowjob that was way above and beyond anything I'd ever given him. So, we finish the 3-way, and afterwards, I ask her about her techniques. She ended up showing me, on my finger, the sort of motions she'd done. I went and practiced on my husband for a few days, and managed to incorporate those techniques into my own repertoire.
Sure, I felt a touch of jealousy for about 30 seconds. But then, I got over it, and gained a serious long term benefit. I honestly hadn't realized I could use the throat muscles in that particular fashion, and that knowledge has helped.