1. (Adj.) A state of being in a relationship where one is not dating the other person yet and is thinking about giving up. They may be close to being in a relationship, but they aren't because one member is in this state. Similar to being "It's Complicated."
"Hey, Are you dating that chick yet?"
"Nah, I'm Dude Guys I Don't Know."
"How's it going with that girl from that thing?"
"Eh, I hung out with her but I think she is Dude Guys I Don't Know."