Slap Arse December Share definition Flag Another month to slap arse!! First to 100 gets £10 by their best friend Tyrone: fam you know it’s slap arse DecemberJohn: you have to give me £10 if I get to 100 Tyrone: klmmm Slap Arse December by yourmumbed November 2, 2019 Get the Slap Arse December mug.