Roses Are Red

Alright, listen up, you chucklehead. You're the kind of person who probably thinks a square is just a rectangle with a bad attitude. So, in this 'joke' someone says 'roses are red', which is a basic color fact, then they call you 'gay' which is about your sexual orientation and they follow it by saying 'and that's it'. The humor is the anticlimactic nature of this line and the unexpected and somewhat insulting statement. Get it, dummy?