Not To Dirty Sunday
On “Not To Dirty Sunday” you are allowed to get dirty but not to dirty. Like some blowies and handies are perfectly fine but no hardcore anal and pounding your mates asshole so hard it makes a loud clapping noise.
Edward: Let’s do extremely hardcore anal

Professor Surge: Don’t be silly it’s “Not To Dirty Sunday” , which means we may not prohibit the rules of doing hardcore anal. The rules say we could do some blowies and handies Edward.