A teenage boy invites his new girlfriend to his place for dinner and to meet his family. She arrives and they sit at the table to eat, with the cute little family dog nestling down at the girlfriend's feet.
She's very nervous at it all and desperate to make a good impression, and she accidentally lets go a squeaky little fart. The boy's father says "Rover!!!"
Shortly, she realises that she's going to have to fart again and, despite her best efforts, the next one has quite a rich, unmistakeable tone to it. Again, the father calls "Rover!!!"
She thinks this is great, how polite they're being and blaming her little episodes on the dog, so she now has no hesitation in letting them go without any attempt to hold them back and does three more horrendous trumps, each noisier and razzier than the last and, each time, the father shouts "Rover!!!"
Finally, she dispatches the longest, noisiest, raspiest stinkiest one known to humankind and the father actually rises from his chair and bellows at the top of his voice "ROVER!!! COME AWAY FROM HER NOW BEFORE SHE SH*TS ON YOU!!!!"