I self-identify as gay but I have had fantasies of fucking women. When I finally had the opportunity to do it, we got naked and then I was like nope, nope, nope. She was attractive too. I lost my boner instantly and was like uh... sorry... I can't do this. I think it was from watching straight porn, where I was focused more on the guy btw, but I still built the association. Porn enhanced my fantasy life. Trying to do it IRL made the matter crystal clear. I'm a big old homo.
Maybe it's that way for you. You might try it and be like ugh... no thanks. Maybe the fantasy is just better. Just make sure you find a dick you're actually attracted to. Nothing is worse than blowing an unattractive dick. You won't be able to figure out if you like sucking cock unless you get a good one. This is what science calls "the control". lol. If you are repulsed due to ugliness then that doesn't rule out you like sucking cock. Make sure you account for all variables.
Now that I'm writing this, I remember being friends with a guy about 10 years or ago or so. Straight, serial monogamist, had a few girlfriends in the time I knew him. He told me one day that he had this inexplicable sexual draw to some men... and it had to do with their sexual energy. We had long conversations about it because he was afraid of talking to anyone else about it. He said male sexual energy is really strong and hot, and it turns him on. Later after I moved away, he told me online that he tried getting with a guy who had that energy he talked about, but the physical side didn't work. So he is straight, but really appreciates male sexual energy.
It takes all kinds.