Ah well, allow me to subvert that suggestion.

Expressly and unequivocally, threesomes are not something I particularly talk about when talking to bi/pan people.

Certainly not any more than anyone else. It isn't something I voluntarily suggest we do, it's not something I expressly ask about. Some of my friends have had threesomes, and some of those are bi/pan. So it's not something I've not talked about, it's just not the first thing that comes to mind.