When a man is extremely sloshed (drunk) and has sloppy, wild, sweaty, loud, smelly, and great sex with a woman. Be advised slosh fucks have been known to occur with fat women, so the morning which follows the slosh fuck may be extremely regretful and or awkward.
Dude, last night I pounded far too many beers at the bar. Then there was a fat woman, who had NFL linebacker potential. For some reason, after a twelve-pack, she looked good. Anyway, I slosh fucked this fat lady for two hours and it was fucking great!