He can be a huge asshole to people,
He's extremely promiscuous.
His abusive behavior towards Fatigue
at dinner, he disrespects his mother.
He says "Shut up!" too much, which is very rude.
He stole a YOLO shirt. and committed various acts (which were illegal)
He is bisexual.
His bad behavior likely came from his bad relationship with his parents.
His name, Sheen, is likely just an alias he goes by whenever he sleeps around.
Hes from the show, "bedfellows"
Hes also very very immature