It’s challenging for many men to deal with their daughter’s emergence into adulthood. The difference between a dad who is working through his feelings of attraction and a dad who is an abuser is all about boundaries. Without knowing more about your family dynamics, I can’t tell what’s happening in your case. Has he crossed the line too far? Or is it possible you are too sensitive to the possibility?
I do understand your concerns. But if you don’t resolve this, you are going to be uncomfortable in your own home until you are old enough to leave. Even then, you will have a very difficult time being close to your family. For those reasons, I think it is important for you to confide in your mom to let her know how uncomfortable you are with your dad and then to have a frank three way conversation that includes all of you. You are all setting the terms for the rest of your teen years.
Before I get a dozen letters expressing concern that I’m defending an abuser: I’m doing no such thing. I’m allowing for the possibility for misunderstandings and the very normal awkwardness that happens between dads and daughters and mothers and sons that occurs during adolescence. A short letter doesn’t provide enough information on which to make a judgment.
I wish you well.