>>5 It'd be kinda suspicious if she did.
If your friends don't believe you right now don't worry. They'll know you were right down the track because faking his own character is not an easy job. And it can't be done for too long.
And if you don't want to wait and they still don't believe you, just say that 'would you be the type of person to dump him over nothing? That sick joke of his was your last straw.'
But only say that if they come ask you again about it. Otherwise if they still don't believe you, just go on the 'whatever' train. Because
>>3, that's how people form opinions. Sometimes stupids ones they'll regret down the track.