oh my dear....this is really difficult situation....I would suggest you talk to somebody....How is your relationship with your mother? Why don't you talk to her?
Probably, your dad is just happy that you are growing up and he's just admiring you!
However, if you have such feelings, you got to say something before anything bad happens....Just put them in nice words.....do you think you can talk to a doctor or priest or some trusted person? oh god, that's so difficult....still, I think talking to your mother is the best way....
good luck
M.