No, it's the bit where Mary wants to be a stallion that gets me, lol, script writer didn't do much research me thinks, or maybe Mary would have wanted to be a mare instead
I think the 'stallion' bit is where the narrator says 'let the stallion within be released' words to that effect probably meaning the lovely black horse adverts that used to gallop on the beach but due to political correctness one cannot say 'black' horse-so stallion instead!