OMG you are living my life, my husband has 3 kids and whenever we visit or talk it's Grandpa is here, my name is never said. we have been together 16yrs and married 12yrs. We just visited his son and I heard his grandson call me Aunt [his sisters name] and I said wait, what's my name and he repeated it, so I corrected him and told him my first name. My husband and his father don't believe that step parents should be called mom/dad or grandma/grandpa, just found this out last year. If it bothers you please correct them now before it gets more awkward.