Troll: "Yeah, it's upstairs, your mom and I were Icing The Cake last night."
Stoner 2: "Here, throw this little bit of weed ontop".
Stoner 1: "I'm going to call this 'icing the cake' for now on." Stoner 2: "You should put that on urban dictionary!!"
Note: only one person can claim having iced the cake per port-o-potty; extra bragging rights if you wipe with a wife beater afterwords and swirl that around your prize to fashion it a makeshift crown of glory