The sexual technique of receving two phalluses at the same time, one in both the oral and anal cavity. The maneuver is performed with two males in a standing position and a female in a crouch position to give the illusion of the proverbial "lamb" being roasted on a spit.
"Man, me and a guy totally lamb roasted this chick last night"
"Yo babe, you want to lamb roast tonight at my crib?"
"Biatch, GTF onta me an' my homie's dongs before I pop a cap in yo' mane!"