Means “What about you”

When a person neglects you for someone else named Lee.

a kid who is super fucking gay

It is used mostly on social media or by people who don't know any other word to say. Most of the time it is used if somebody says something funny or if the speaker just wants somebody to shut up after talking.

Continually slapping an unsuspecting victim in the back(usually in between the shoulder blades)in a motion that is similar to a drumroll.