Oh there are actually quite a bit. I’d say tops of that list is probably a threesome between non-relationship type partners. I don’t want jealousy as a component in that situation.
One fantasy I have is to have full blown public sex in a country and location with no indecency laws and only adults around. I love exhibitionism and public sex so that would be hot. Not sure I would do it given cell phones and all, but it’s a fantasy.
Those are just two of many.