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 like fucking 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.