To love greatly. Originally associated with music. When one is obsessed/near obsessed with something and goes on about said-something or can't stop listening to said-something . Also used in conjunctment with other sexual terms abused in a similar way
"Bills Bums milo to t3h max0r"
"gawd, i bum Tool too much. They cause me to climax *goes red* "
" stop bumming Brian, your gonna rip his intestines out"