When I was growing up my Mom and her best friend, Mary Lou, did everything together. Consequently, her daughter and I played together and were the best of friends too.
Go 18 years ahead. I pledged Alpha Phi. Imagine my surprise and Miss Mary Lou's surprise when she learned that I joined a sorority--her sorority--Alpha Phi. I honestly had no idea she was even in a sorority! Turns out she AND her two sisters were all Alpha Phis at the University of Texas - Austin (Omega chapter).
A few years later, my Mom joined Alpha Phi as an alum initiate.
It's not exactly a chance meeting, but it is a surprise chance discovery (and, I think, a neat thing).
AOE,
Jen