Dating is rough. Watch a sitcom if you don't believe me. There are a lot of weirdos out there, and all of them are looking for love. So us "normal" people are constantly on the lookout.
So, what are the signs that you are on a date with a weirdo? Here's a simple test. Ask yourself if they are weird and unpleasant to be around. If the answer is yes, then do not go out with that person again.
It may come across as obvious, but it sure wasn't to these folks.