The phrase "Are we dating the same guy?" commonly refers to a phenomenon centered around Facebook groups where women share information about men they are dating or have dated to see if others are, too. These groups started as a way to check if a potential partner was available or single but have since evolved into communities for exposing serial cheaters, warning about abusive behavior, and sharing dating experiences. The groups often function as a form of online vigilance and support among women, aimed at protecting members from untrustworthy partners. They have strict rules to protect privacy and avoid defamation by restricting posts to a man's photo and first name only. However, these groups can also lead to negative perceptions and scrutiny of men, sometimes involving speculation that can impact reputations without accountability. The intent is often protective, but the social dynamics can be complex.

So, when someone asks "Are we dating the same guy?" it usually means checking if two or more people are involved with the same man, often using these kinds of shared community resources or conversations to find out.