Am I really bisexual?

So a bit about me. I never really had any thought that I could be queer for most of my life. I remember looking at one guy in a locker room back around when I started puberty and getting turned on around my best male friend around then. I later remember having thoughts of "i might like to do this guy" with him, though I'm not sure if those were legitimate or because I was afraid I might be gay (something I'd kind of been troubled about during middle school as a result of religious propaganda and homophobic bullies looking for any sign of weakness). Aside from that I was mainly interested in girls, and avoided gay porn and such.

I remember around 2006 I looked back on my past, thought about the incidents above, and concluded I might be bisexual, but dismissed it because I thought it was too rare to apply to me. Three years later, when my then-girlfriend asked me about my sexuality I ended up confessing to her that I had feelings for guys, and started identifying as bisexual and coming out to people as such afterward.

Seven years have passed since then, and yet I'm having some doubts. I have only ever dated girls. After the girlfriend mentioned above I dated three more. Only one was cis though, the other two were both trans; one had been on hormones for 18 months and wasn't sure about getting SRS, as she was fine with using her original parts for sex and was terrified of surgery in general, the other (my current girlfriend) is pre-everything, is clear about wanting to change all the way, and trying anything sexual makes her really uncomfortable. I am to understand though that this isn't really evidence in favor of being bisexual; since they're women and I consider them women, there's nothing non-heterosexual in wanting to be with them regardless of parts or progress, or so I am told.

As for what I have done with guys since coming out, I have flirted with a few, asked a couple out unsuccessfully, kissed one, and done a lot of heavy making out with another. I did enjoy all of that, but the fact remains that I'm not sure I can see myself in a long-term relationship with one. In fact, it seems like it's only younger guys, mostly androgynous ones, that interest me. Anything involving big hairy guys or older guys is a turn-off to me. Also, I find that when I'm asked what male celebrities I'm attracted to, I can't name anyone specifically.I feel as though I'd still prefer girls to guys overall, were it not for a strange thought that I like male genitals more than female ones.

As a side note, the above statements about preferring women yet also preferring male genitals suggest I have a rather disgraceful reason for dating trans women, and I can't exactly deny this. I know it's not much of a defense, but I would never want my girlfriend to give up her happiness and sense of completeness just to satisfy any kind of desire on my part. If she needs to change something to be at peace with herself, I would never stand in her way. Still, I can't help but be ashamed of myself for this.

Regarding everything I've said, it seems to me that I primarily do prefer women and always have. The question is now whether the limited feelings and things I've done with guys really make me bisexual, or whether they're just the result of taking adolescent fears and doubts seriously combined with a desire for intimacy of some kind, in an "It still feels good, even if it's not with a girl" sense. Any thoughts?

 

I've generally been identifying myself as a 2 on the Kinsey Scale, but that's still due to me being uncertain if I actually am attracted to guys or somehow just want to be.