Stupidest conversation ever

My friends were having the most stupid conversation that I could ever imagine! And ironically, they were talking about how stupid the other was.

Friend 1: You're so stupid!
Friend 2: No I'm not, your stupid!
Friend 1: You're stupider!
Friend 2: You're stupidest!
Me: Stupider and stupidest are not words, therefore, you are both very stupid indeed. 

Of course, they didn't have anything to say after that.