I second autumn.
If it were MY father the answer would be simple-he ALREADY KNOWS so don't worry about it-just be yourself.
IF it were my sisters father it would be -just don't say anything about any topic deeper than the current weather.
IF it were GG's stepfather it would be -RUN just RUN the other way like Forrest Gump.
If it were Maca's father-It would be-dude you can't shock him, he's at least as kinky as the rest of us-don't worry about it, be yourself.
SO you need to ask her what the case is with HER father.