In an online FPS game, to stand over the warm corpse of your opponent and repeately squat up and down in a display of dominance. This activity is usually accompanied by screaming something such as "You are owned, biach! How do you like that shit, fucker! Huh! Huh!" Ideally, this childish display of bravado ends abruptly with a sniper shot to the humpers head.
"Mom, you're messin' me up! Now CaptainUnderpants is corpse humping me! Get me some fuckin' chocolate milk!"