A sexual act involving a minimum of 4 participants, one of whom being a girl.
The 3 men occupy the three main orphases and coordinate their movements so to simultaneously ejaculate 'filling' the female instantaneously. Thus expanding the female like the bird from shrek in the scene in which fiona sings until the bird expands and explodes.
dude 1: 'dude, shes fair hot'
dude 2: 'i reckon we should shrek bird her'
dude 1: 'ok me, you and who else?
dude 2: 'how bout garth?'