All the lingo isn't that important in my minds eye.
Rather making sure that the 3rd party is truly BI.
And being spontaneous during the enjoyment.

And then we can call whatever we'd like.  

Threesomes and moresomes can definitely be a lot of fun with the right kind of uninhibited friends!

As a genuinely bi trans provider, I frequently get inquiries from couples (or from guys interested in doubles) who are interested in certain physical combinations but who don't necessarily want another masculine body in the mix. Best of both worlds to some, I suppose.

I wanted to expand further, as I meant to express it in my original post.

The truly BI man, would need to be Spontaneous and  open-minded.  

I want the experience to be erotic, spontaneous,  uninhibited, without shame.

It's not always easy for a man to explore the taboo side.   This is why we have this adult lifestyle.
Where you're anonymous to the other, but me.  You can feel safe. (I screen all parties partaking).

Where (at least when you're with me) you can enjoy, guilt /shame free.  You can let your hair down and just breath and explore, unleash your inhibitions and yes, fucking enjoy yourself.

Life's too short not to.