Definitely not bi or gay (unless they're sexy 2D girls, but that's more of an admiration if anything), but I used to obsessively watch lesbian porn. It just worked so well for me because it was easy to imagine me being in that position. Dicks in porn is yucky imo, lol. Plus I don't like to look at random dicks. It's like watching a good porn and just when you're about to come, they zoom in on the dude's ballsack.
Like if I was into a bi dude (he's bi) and we had a threesome with a chick I couldn't imagine how much they'd both laugh if I said "It's not straight if I don't graze her clit."
In a common realistic threesome you wouldn't be DPing her anyway. Or maybe
you would, but I think a lot of people have misconceptions of the common threesome.