My fiancée parents are divorced and remarried. We are looking at getting all of our parents wine glasses and beer mugs as thank yous and we are addressing my parents as the M/F of the bride and his mom and dads as M/F of the groom. Is it proper to address his step parents as step-father/step-mother or do we just leave them blank. I just don't want to offend anyone and not sure what to do.