When I masturbate, I have to watch girl on girl. I get really turned on by girls in youtubes etc. But I'm straight.. I only hook up with guys and have crushes on guys.
It takes two things to have a sexuality defined:
1. Desire.
2. Action.
To be straight, gay, or bisexual, you need to both desire the specified gender(s) and have had encounters or actively want encounters.
It sounds like you're just turned on by porn. I had a friend who was disgusted by pedophiles, but enjoyed looking at porn that had children in it. Some people are turned on because it's taboo, not because they want it.
im the same way, but ima guy, i gotta watch 2 dudes analing and rim jobbing each others @sses all over for me to climax. but im totally straight too. ask my girlfriend. she thinks my tractors sexy