(n) A male between the ages of 15 and 25 that one cannot fux with. It is comparable to the word "fuckboy", however a "cux boy" is simply intolerable to anyone with any semblance of social standards.
Greg: Yo i can't fux with that kid, hes such a herb
Ben: I know bro he's such a fuckboy
Greg: Na son, we're fuckboys, he's a cux boy
Ben: Word... cant fux