Ever since I've begun to mastrubate, I started noticing how hot my sister is. By the way I'm 15 and my sister is 17. Anyways I like to wait until she falls asleep and then go to her room, sit by the bed and mastrubate. I sometimes even open the shower door and mastrubate to her silhouette through the shower glass. She's actually cought me a couple of times, but she never realized it was HER I was mastrubating at. Funny thing is, I'm not a lesbian, and I don't think I even bi, because my sister is the only female I'm attracted too.. lately I managed to convince my sister to mastrubate infront of me while I mastrubate infront of her. I think she's turned on by me as well. This one time we were THAT close from making out. Is that normal? What should we do?