Is ual abuse hereditary?

Umm when i was 13 i was molested by my brother scott. Now my brother stephen who is 16 has started saying some very inappropriate things to me like making jokes about me, and whenever my boyfriend is over he "checks on us" almost as if he is jealous, i also catch him looking at me all the time. He is really creeping me out. I have tried to talk to my father but he blows me off. He SAYS ITS NORMAL. but im gettin fed up