Grandpa names for someone unrelated...

What are some ideas on what to call someone who is not related... let me explain my husbands mom and dad are split and they are both living so we don't want anyone taking place of the real grandfathers but we don't want to hurt anyone's feelings by her new husband not being called something so what's some ideas you have? I can't think of anything the biological grandfathers are going to be paw and pepaw. If I had my way the kid would just call him by his name bc he doesn't really know us and has nothing much to do with us...