Having to put one's mouth over the top of a newly-opened beer bottle/can in order to prevent overflow. Looks quite like a clumsy blowjob, hence the name.
When a person makes a sandwich of 2 sponges around a latex glove, stretching the wrist of the glove back over the sponges creating a crude prosthetic vagina or replica prolapsed rectum.
The same person then squashes the "gammy fanny" between the toilet bowl and toilet seat in order to be able withstand the rampant thrust of a sex craved ginger persons pelvic motions in full rape mode.
To take something small, that doesn't quite qualify as a theft. Probably from the Danish "skæv" or the Dutch "scheef", both of which are pronounced similarly, meaning "askew, or not quite right'. To change an item's ownership without permission, but only something small and of little worth.
"I skeefed an apple off the neighbor's tree." "I skeefed some chips outta your bag when you looked away." "Don't skeef my chair when I go to the bathroom."