When two people strip, they then fill a one person sleeping bag with petroleum jelly. They then both enter the one person sleeping bag and wiggle around on the floor sometimes leaving slug trails. Can be both sexual or nonsexual in nature.
"Whoa, did you hear that Miller was sleep sluggin' with some dude last night?"
"Yea that dude slugs all the time."
"Yea that dude slugs all the time."
by sabres56 September 26, 2015