Before our oldest grandson was born, my husband started calling me Granny and taught him to call me Granny also. I wasn't thrilled at the time but got used to it. When DGS was learning to talk, my husband would ruffle his hair and say, "You're my Best Buddy". DGS started calling my husband Best Buddy and that has also stuck. He is now 16 and still calls him that. We are Granny and Best Buddy to all of the grandchildren. Both sets of parents were Grandpa and Grandma(last name) to our kids. Sometimes my MIL was Just Grandma to our kids because the Great Grandparents lived on the same farm as them.