1. “Borrowing” people’s bikes. Even if you return them after.
I don’t care how drunk and carefree you are, this is not nearly as whimsical or adorable as you think it is. This is not Oberlin, you are not Zooey Deschanel, and nobody is going to be delighted by the sight of you riding off into the sunset on their bike, your vintage housedress fluttering in the breeze as Belle & Sebastian plays in the background. Either ask to borrow it, or walk.