if s/he
... is not asking you out,
... is not calling you,
... is not dating you,
... is not having sex with you,
... is having sex with someone else,
... wants to see you only when s/he is drunk,
... doesn't want to marry you,
... is breaking up with you,
... disappeared on you,
... is married,
... is a selfish jerk, a bully, or a really big freak.