Doing the "j-diddles" means a person is drooling over the sight of a huge man arse,
while at the same time emitting a high pitched drone that resembles the sound of hitting a baby with a bag of cats.
Jeff: Hey does it sound like someone is in the middle of a j-diddles ?
Vinny: Ya , theres a mouldy twat over there salivating at sumo wrestling diaper bloopers.
Jeff: Ahhhh flip it down ! thats mank !