When you and your friends (your best friends preferably) fill different water guns with different sundae toppings (usually whipped cream, melted ice cream, chocolate syrup, and carmel sauce) and team up on some one and spray them. After that put a cherry on top. :)
Cami: Hahahahaha! Look at that guy!
Jenna: Yeah he looks like he just got Icecream sundeathed!
Cami and Jenna: PWNED!!!