A person who secretly watches a lot of porn or knows an excessive amount of sexual things and it’s completely opposite to the persona they show people.
John was cool and all, but I found out he was a freaky bum.
Sarah’s a freaky bum she watches porn like everyday and is still horny!
The act of setting on fire one's fart and lighting a fuse on an explosive with said fart.
Billy set off fireworks on the Fourth of July with his explosive bum breathe.
Easily angered. Lookin' fer a fight!
Child: I hate math homework!!
Parent: Now, now... you're as cross as a bear with a sore bum.
When a male ejaculates inside the female anus.
i made my girl have a right milky bum last night!!
An act of brotherly love involving two fraternity brothers seeking true brotherhood. One brother grabs hold of the other's bum and proceeds to "rump it".
Hey did you hear about the U of A SAEdogs?
Yeah I heard they switched their focus to bum rumping.
Tunkle bum is the action of looking at a Volkswagen Beatle whilst crying over the movie up
John commited a tunkle bum after exiting the theater