When, usually at the bar or a party, a guy (your buddy, unless your a total dick) goes for a broad, but you call out something that won't give him a chance. It's usually about an STD or him having a wife.
The opposite of being a wingman
"The Gil sewered seabass so bad at the bar last night!"
"I just fuckin', sewered the bastard when he went to pork my broad."
(At the bar) "Hey BUDDY? Have ya told her about your HIV?"
Drunk/stoned, Angry, Confused, or any other state of being that's compairable to how you'd feel if you suddenly found yourself in a sewer.
drunk: "Man, I got so sewered last night, I have no idea where my shoes are."
angry: "That drive's left me so fucking sewered!"
Confused: "wait... I'm sewered... what the fuck are you talking about?"