What would it be? It just happened at "our" club (see reference).
On the ground floor of the castle (more like a very large mansion) next to the entrance hall, there was a quiet room with large sofas. Clearly destinated as a place to relax or play together.
Two men sat down opposite us and started playing with each other. But that didn't last long. One of the men took the other's penis in his mouth.
I knew my wife found it very exciting when men had sex with each other, and she responded by playing with herself.
When the men switched, she got up and joined them to help them, but also to participate. A third man entered the room, looked around, and decided to join the trio. So a MMMF situation arose.
My wife took control. Like an experienced mistress, she made those men satisfy each other with their mouths. It was remarkable how those three men cooperated, or rather, did what she wanted them to do. She regularly pushed a head towards a penis. She herself also regularly took one of those penises in her mouth.
What excited me most was that she jerked off a cock with her hand in another man's mouth. And that's how it ended. Possessed by the spectacle, she wanted to experience it too.