Well here's the important caveat: If the sistah does not tell that she's dating a bruh from another chapter, she's fair game. Also, if she does tell you that she's about to be engaged and marry a bruh from your chapter (say he was a sPhinxman at the time), she is fair game.
As you've probably figured out, both scenarios happened to me as an undergrad and I refuse to be blamed for a sistah that presented herself to me as unattached.