Whats he longest you will grind/make out w/ girl before you give up?

[Halfpoint]

A couple of weeks ago I was making out with this really cute girl and dry humping her in my bed for hours. Every time I reached down to caress her vagina, she moved my hand away.

AFter about 20 attempts I decided to quit, but she jumped on top of me and continued making out w/ me again.

I asked her "whats wrong?" a number of times and she just said that she "wasn't like that" [img]/images/graemlins/mad.gif[/img]

Whats the point where you should just give up and call her a c*ck tease and walk out?