4. DON’T Expose Her Father’s Double Life
This one is always a difficult temptation to avoid, as you just want to help. But think this through. If you find out that your girl’s father is a commie double agent, philanderer, transvestite, pedophile/cat lover, you need to fight the urge to reveal that information dramatically at the dinner table. You may think you'll come out of this looking like Inspector Holmes, but you’ll end up looking like that French detective, the one who fucks things up. People just don’t want to accept something they aren't ready to hear. Plus, Pops might have five passports, meaning he won't be going to jail after he murders you.
Pro Tip: If you are going to go against this advice and expose the duplicitous daddy, hog tie and gag him beforehand. This limits his potential avenues of escape.