When somebody who is uncircumcised pinches their foreskin tightly together before they urinate, causing the urine to collect inside their foreskin. When the urine collects inside of their foreskin, they release all the urine in less than a second like a grenade activating; which is why it's dubbed the "Skinnade"
Nathan: I'm releasing a Skinnade! oh my god!
Jeffrey: What the fuck Nathan that's gross!
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi