Men's underwear can be a deal breaker too. If one decides to rock boxers, all I imagine is your nuts free flowing and boxing each other all day. Tighty whities that look like an over sized diaper are no good either. Usually running a size too large, inevitably have skid marks and leave way to much room for an assumed undersized package.
Lastly I have to address camel toe. You can feel it and it's less offensive to just pick it than leave it. Otherwise you'll end up in a meme!
Just say no to granny panties, period undies and boxers with cartoons.