Fartburglar
A person who farts right after you and steals your thunder, so to speak, claiming they are responsible for the horrible smell when it is really you.
you fartburglar!
fartburglar
n. a burglar that steals things and farts in your house. often the house-owner gets accused of for the extremely toxicating smell
I didn't fart, it was the fartburglar