the act of sucking someone off while they are pissing inside of your own mouth
truman: yo sadyis u tryna go yussing
sadyis: hell yeah dude i love your yuss
truman: type shit bro see me after school for a yussing session
funching, the act of sucking your own penis
yo truman u tryna go watch the new godzilla movie? nah bro im funching
the act of playing with your chode in class when your very bored and have nothing to do
person 1: yo bro im boutta start yisking this class mid af
person 2: hell yeah bro lemme get lookout