One thing to bear in mind is that our sexual classifications are socially determined. In plainer English, to be 'gay' means certain things today, although even there we might find gray areas around certain behaviors. But down through history, and across cultures, the labels vary. In ancient Greece older men could have intercourse with younger men, and neither would be thought of as exclusively or even primarily homosexual.

I find the whole subject of categorization bizarrely fascinating, including my personal attitudes. When and where I was raised, gays never registered on our radar screens. I consider myself very open to a variety of BCD activities, including the idea of more than one guy involved with one gal (never done it, so don't really know how I'd react in person.) But the idea of engaging with another guy is totally out of bounds--couldn't even look at it when a seen might show up in the old days of porn. I've no problem with anything consenting adults do, but my boundary sure stops short of that. And I'm not sure why.