[gringochileno]

Seems like this line is good for getting information about how likely she is to put out, but doesn't do much to actively get you closer to sex the way some of the other answers do (e.g. "I've only known you 10 minutes and you're already telling me about your problems" and "I don't care"). It's a good strategy from the standpoint of screening girls for fast sex, but if I already had a pretty good idea of a girl's willingness to cheat I'd be inclined to either go with a witty response or just ignore it. Overall a very solid option that I'll be adding to my toolbox.