The act of two people without limbs having sex. Sometimes there are people that aid the "nuggets." They are called "nugget helpers" or "McNuggets" more commonly on the streets.
Ryan: Man.. I was watchin' these two nuggets goin' at it last night... I just...
Ari: Dude. What the fuck is wrong with you? Who watches nugget sex anymore?
Bert: Fuckin' pole smoker.
A nuget in this case is a quadrapaleigic having sex with another "nugget". An exclaimation of shock. As one might guess there is usually a third person aiding the proces.
aw nugget sex! I dropped the vase.