'The Girlfriend' confusion?

[Youngdays]

Alright guys i never really understood this so please help me.
But in the episode the girlfriend when they're sitting on the coach at the end after the plane had hit Cole n stuff and Frank's going 'it's funny isn't it? I had my bags packed for Adelaide, but it turns out we're both in the same position. As far as *hand gesture* is concerned' and Cole says to him that he's wrong, like Jenny wasn't real she was fake but he still really isn't a virgin.
I don't understand, it's not like Frank knows Cole in lying yeah? So he can't be angry at him for that, because as far as i can tell at the end when Cole stands in front of the 'virgin' sign thing Frank looks surprised so he really though Cole wasn't a virgin.

SO WHY does Frank get angry and leave at the end? LIKE i mean it's not like Frank can be angry at Colin for the fact that he's had sex and he hasn't, so what IS he angry about. Why does he leave in a huff, cos he doesn't seem to have a reason anymore after the whole Jenny thing is resolved between them

[Lauren]

lol.. I always saw it as Colin had been gloating about it the whole episode and yeah i guess Frank sort of doesnt believe that Col has had a.... doesn't think he's had a....

...but Col is a bit proud and boasts about the fact that 'he's had a...." and he sorta teases Frank and makes him feel bad so thats why I think Frank gets mad at Col... and he feels bad so he tells Frank the truth which is a weird way of saying 'I'm sorry"

That''s my opinion anyway lol

[chantal112]

thats what i thought - frank was sick of col boasting and teasing him

[nyandra]

Frank knew Col was lying by that point. Is what I always believed.