If you ever receive a dubious excuse from a girl who has cancelled a date at the last second, the best reply is an ambiguous one that could be interpreted as either sarcastic disbelief or sincere sympathy. For example,
GIRL: Sorry I can’t make it! My grandma fell and can’t get up. I have to take her to the hospital.
That’s it. The insidious beauty of this one word reply is that, in the event her excuse was genuine, your muted exclamation can easily fill in as a plausible expression of condolence. If she’s lying, she’ll be psychologically self-groomed to interpret your “wow” as a jerkboy dismissal, and your value to her as a sexual being will go up.
“wow” is a great all-purpose ambiguous message that can springboard into all sorts of flirty conversation.
GIRL: You don’t believe me? No really my grandma fell.
YOU: ok. say hi to grandma for me.
GIRL: don’t be such an asshole.
YOU: wow that sucks. I hope she feels better.
You can really screw with a girl’s head if you’re familiar with the art of ambiguity.