I read, in your other post, that you're 15. I think at that age everyone has confusing thoughts around the subject of sexuality. Plus nowadays when there's such easy access to pornographic material of all sorts, plus what one can see in movies and even on TV, it's to be expected I think that thoughts such as those you're struggling with are bound to come up. (By the way, internet porn can become addictive. And it can, in some cases, make it difficult to derive satisfaction from sexual experiences with real-life partners. It would probably be best if you could bring yourself to not watch it at all if that's possible.)

You asked if the thoughts you're having make you bisexual. At age 15, I would say it's too soon to make that kind of judgement. Perhaps you are (or will be.) Or maybe you'll find some other resting place altogether on the sexual orientation spectrum. (There are many.) Perhaps this is simply a phase you're going through with all those teenage hormones flooding your system. Time will tell, as the saying goes. There's certainly nothing wrong with being bisexual if you come to the conclusion you are as you mature into young adulthood. But for now at least, my thinking on this subject is that you simply wait and see how things develop. And again, if possible, refrain from watching porn. It's doing you no good, just adding to your confusion regarding your sexual orientation. My best wishes to you...