when one who is partial to sleepwalking, whilst horny, accidentally bums another in their sleep. (male/female/sheep/ect) sleep bumming.
a prime example of sleep bumming would be a person suffering from sever sleepwalking, who had fallen asleep next to their best friend after consuming 3 viagra (for fun) this person would then proceede to "sleep bum"
by ineedtogetagrip December 30, 2010