One time I was at the store with my wife and our two children when we ran into my old girlfriend from high school. I dated her for three years, from sophomore year to senior year when I left her for the girl who would become my wife. Needless to say, it was rather awkward when we met, but she had grown up into a delightful woman and was very nice to all of us, even to our kids. My wife was a little bristly towards her at first, but soon calmed down, and a moment that could have been horribly awkward ended and the crisis was averted.