unsocial
Example:
Brennan: "Hey do you want to go to a really cool place tonight?"
Michael: "naaaa, I think I'll pass"
Brennan: "You're a pretty unsocial person."
Brennan: "Hey do you want to go to a really cool place tonight?"
Michael: "naaaa, I think I'll pass"
Brennan: "You're a pretty unsocial person."