The most insane, most mad, most versatile insult every created by man. It can be used in any sentence and is the most painful thing to ever hear anyone say to you. If someone says this at the perfect moment, it is said that the receiver will immediately die from cardiac arrest.
Guy 1: Bro you are so overweight, you need to work out, and you gotta brush your teethyour breath is disgusting. Dude, I'm really worried about you, you're addicted to crack, and heroin, I want you to get better-
Guy 2: Your mom gay
*Guy 1 dies*
'is your mom gay' is a common question asked my bullies at school. A correct answer is 'which one' but if they hit you with the 'both of them', you are fucked.