accompanied with an eye roll can be used to bring your friends back to reality when start fantasizing about your mom.

A phrase uttered when some one does some thing stupider than stupid. stupid. Often said by Milhouse Van Houten on the Simpsons.

A person who is more stupid than a regular stupid.

the act of being stupid and retarted

Someone who looks up "stupid" in the Urban Dictionary.

The perpetual trademark of our species. The random and unpredictable state of mind that causes and governs wars, unwanted pregnancies, political actions, divorces, ripoffs, reality TV shows, copycat crimes, cults, self-injury, and lawsuits.
Since the stupid in our midst are breeding uncontrollably while the intelligent minority are dying out, one can easily predict that our stupidity will far outpace our technological progress within a few decades, and propel us back to the Stone Age or extinction with in a few centuries.

You is stupid.