My granma used to work as a teacher on the university where I also teach, so from time to time she will say she knows somebody that I also know.
So, once she asked,
-Hey Fer do you know XXXX?
-Yeah Lalu, he is the faculty director.
-Oh! He is a good friend of mine! he was my teacher and he got married with one of my closest friends.
The same day, as I walk into his office, he asked me:
-Is XXX your granma?
-Yes, she is!
We got a good relationship, since he was always teasing everybody whenever he teased I just threw my granma card…as, did you know that XXX was my granma teacher? and she is over 75yo.
P.S. 1 : At the time I was a student not a teacher.
P.S. 2: Yes I continued to throw my granma car even when he was my boss’ boss.