Dudes: No sleeveless tees over long-sleeved ones (even if they're attached and it's supposed to be a "look"). In fact, better yet: No sleeveless tees, period.
If one of the parents of your date asks for either a private dance performance or a private dance lesson from you, quickly but tactfully get your date back by your side to immediately dilute the creepy factor (just as JP did with Andi's mom).
It's 2014. You don't need to ask anyone's father's permission to propose marriage. But if you insist on asking for a blessing (or the more confrontational "Would you welcome me into this family?"), then ask both parents, not just the dad. (This applies to any ladies considering proposing as well.)
Renee's mom said it best: "We can love our pets; but you need to be in love with the [person] you want to be with." Make sure you don't just have a "pet," or that you are the "pet."
Don't meet the child of your date unless you're sure you see a future together. And certainly don't meet the child of your date the day before you dump them!