I always find that banging a girl before you get to know her is guaranteed way to lose interest in a woman. At first there is lust and after you bang the lust is gone.
You need to build up a friendship with a woman that ultimately leads to you caring for or loving her, that way after sex the friendship/caring/love is still there.
So I see where your coming from. But you should defo bang the Mexican chick. Why not, think of it as getting some practice in for when you meet that special person.
As good friend of mine used to say... 'Every holes a goal!'