Talking to a girl earlier who has a boyf

I was explaining to her how a guy can get with a girl and the girl can be attracted and then he can lose her cause he gets into the mode of not wanting to lose her and stuff...

She then told me how her boyf was shagging a girl before they got together and she was attracted by that and that he didn't care but he told her it was a learning curve..

She asked me if I'd finish a girl if she cheated on me in the first week of going out but had been going out for like a year...I told her I'd finish any girl if they cheated on me because I could find another girl quite easily and I'm not scared of losing any girl...she said her bf was pissed off and stuff when he eventually found out...her mate just cheated on her bf too and I called him weak for staying with her (exactly what her bf did) and she agreed...

So is this a good way to tool on a bf? By making it seem he did a weak thing...

Also what's your views on discussing PUA with girls for e.g

Telling a girl you're not scared of losing them if you went out
Or that you wouldn't care if they cheated etc

Logic and being human don't mix. I can't say a guy is weak for staying with a girl that cheated on him nor can I say that he is strong for leaving her. As long as you haven't been in that situation, you can't say how you'll react. Maybe the guy doesn't care at all, he just likes the sex. Maybe he leaves her and gets back with her later. Who the hell knows.