Rusty Trigger 

When a male is partaking in anal with another man, he finished then pulls out with crusted feces on his penis then the second participant licks the feces off of the first man penis

I rusty triggered John last night - Carl

Rusty Trigger by ToldYouJack June 17, 2018

Rusty Trigger 

Also known as a "fish hook", a Rusty Trigger is when one runs their finger used for the hook up their ass crack and inserts in into an unsuspecting mouth.

Unbeknownst to Marge while she watched The View, Harold snuck behind her and got her with the Rusty Trigger.

Rusty Trigger by One Pump Lover August 22, 2016