When I first started masturbating I was about 14. I used to masturbate with my cousin (boy) all the time. We used to watch each other and masturbate each other. As time passed by we stopped doing that. However, sometimes I can't stop masturbating while thinking about us masturbating each other. I masturbate to girls all the time also and I like girls a lot but im scared that because I can't stop thinking about him I may be homo or bisexual. I want to be entirely heterosexual, I don't want to be attracted to guys at all and masturbating to my cousin just scares me and makes me nervous. Is this normal? how can I STOP this behavior? is it just because it was my first sexual experience and I got a lot of pleasure out of it? Thank you.