When two gross fatties end up in bed together after a drunken night out. The man will insert his ample fist inside his good lady as he's too lazy to nail her, but after a couple of exerting thrusts falls asleep due to excessive cakes and pies and the fact they repulse each other that much.
The fatties awake in the morning...
Sarah : Chris please remove your fist from my vag!
Chris : Sorry love, i really am a sleepy fister.