#18: The Stalker
This story isn’t an example of an annoying coworker. Rather, it’s a case of an infuriating customer that won’t go away. The OP shared that this guy shows up at her workplace to harass her married coworker. Apparently, he has a thing for her and won’t take “no” for an answer whenever he asks for her number.
Newsflash: “No” is a complete sentence. He doesn’t seem to understand that concept because he showed up wearing a shirt that makes his intentions very, very clear. If he had this shirt specially made for his annoying visits, that would be extra creepy. Hopefully, the OP and her coworker were able to safely get rid of this guy because his insistence is kind of scary.