Paradox. Tell your parents MLP's history - their director (Lauren Faust) is world-famous for her other shows, many of them gender-barrier-breaking (power puff girls, Foster's Home
For imaginary Friends).
And also, if they have even the SLIGHTEST bit of human in them, they'll recognize the name "John DeLancie." And if they don't, tell them Q's in the show. AND, on top of that, they actually got Princess Diana's (I think, whoever the latest one was) wedding planner to help develop their latest episode (S2 finale).