A steady stream of blood that pools in your anus until it eventually gets too large for your anal cavity to hold and it explodes causing the blood that was in your anus to go all over the place.
Anus marinara is the blood and shit mix that comes out of ones asshole after intensely rough gay sex. Anus marinara occurs after gay sex with 3 or more dicks in ones asshole.
While stimulating someones anus it can occur that the anal area, in particular the anus it self, can get glutinous. This causes the skin of the receiving part to stick to the skin of the active part. Anus-flour can help in this regard, presupposed it is worked into the dough correctly.
Carl:"Man Lisa i really like eating your ass, but your skin gets stuck on my tongue all the time."
Lisa:"No problem Carl I have some anus-flour with me."
Carl:"Thank you Lisa! This will assure that we both can enjoy our sexuality."
Lisa:"Yeah! But just make sure to work it into the dough correctly."