A Spencer
A Spencer is a guy who'll be your best friend if you don't piss him off. But if you do, he'll yell at you like you owe him money. He's cute, he's smart, and he's the kind of guy who'll help you cheat on tests but will laugh at you when you fail.
Spencer: 'I'll help you with that math test, but only if you help me with my crush.'
Spencer: 'Why did you fail? I told you to study!'
Spencer: 'You're my best friend, but I swear I'll beat you up if you keep failing.'