Your mum gay means your mum gay. Its a sentence that was commonly used by a youtuber named NFKRZ.
"One russian counts as 5 people" Said NFKRZ "Why did you die first" Jameskii said "Because your mum gay"
It means that your mom is gay. A retarded sentence that's used by NFKRZ
Kiisily: Wow. NFKRZ: Shut up Kiisily. Kiisily: Fucking cunt. NFKRZ: Kiisily, your mom gay