Is there a connection between Alpha Delta Pi and Phi Mu?

[sarahsmilehawk]

I recently met my boyfriend's grandma, who is/was a Pi Phi at Texas. My bf had told her a lot about me already, including that I was an ADPi. She was so excited to hear he was dating a sorority girl.

But when I met her, she and her husband (a Phi Psi) both started their conversations with "So you're a Phi Mu, right?"

My school doesn't even have Phi Mu, but I thought it was such an interesting mix-up because ADPi and Phi Mu have so much in common!