I even feel that, too, sometimes...and my sorority doesn't have an official "brother" fraternity...it just depends on the campus, I guess. For example, at my school, our older girls and officers have parties, events, etc. with two frats I (along with my pledge class) ABSOLUTELY HATE! But, on our campus, we have this "loyalty" to them, so these guys I would normally have nothing to say to, I feel the need to at least say hi or smile.
Oh, yeah...and I had heard all about the "Indiana Love" between SGRho and KAPsi...which is pretty cool to me.
Were they founded at the same school?