Batchelors and Spinsters. An Australian term for a semi-formal get-together in the outback. People dress up in formal wear and go to someone's barn or shed to dance, get drunk, hook up and pass out in the back of a ute (trayback vehicle). Although it sounds rough, it's for private schoolies mostly, because of all the landed gentry.
'I hooked up with Sharon at that last B&S out at Jack's place.'