I had several in my twenties.

Had a bi girlfriend. She'd bring around her friends every weekend. Had dozens of threesomes with about 5 different chicks.

Once my gf got past the jealousy the first time after that it was awesome.
Im decent looking, was pretty jacked in my twenties and have money. So the girls were super into it.
If you want to make the most of it you have to be dominant. I hate when I see some dude getting a threesome in porn and he just sits there like a stunned fish.
I swear something changes in the girls psychology when they as a group are getting fucked by one dude.
That's why you see some dudes able to form harem sex cults and shit. Normies be like how... but it's in our brains somewhere.

It goes bad in the long run. If you're with a good girl you intend to keep around. Don't do any of this shit. It always fucks the relationship long-term. Unless you're both degenerate filth idk.

Had a few threesomes with whores but it's not the same.

Its also fun when we'd be out together and the girls would hang off me and you could see other dudes trying to figure out wtf was up.

Just wish I had filmed some videos or something.