The only perfect comeback that is uncommonly used against the devastating phenomenon called Ur Mom Gay. Can only be used for 2 times in a row or else it will no longer make sense and make you look likefucking retard.
"no u" is the worlds best answer to every "ur mom gay". It also is very good for answering the higher forms of "ur mom gay" such as "ur dad lesbian", "ur ancestors incestors", "ur god a frot", "ur niece obece" and so on. But be very very careful using this word, it could make someone die instantly.
The ultimate comeback back, that is normally used when there is no other comebacks to be made. By using the comeback "no u", you instantly win the fight/argument, unless the opponent pulls out a reverse card, if this happens you just run, you run away as fast as you can.