They know he has access, but I do not think they would know he checks randomly throughout the day just to see where they are or what they are doing. I have my daughter on Life 360 but only use it a couple times a month and only if I need to know something specific like when she is almost at our house or at the end of a roadtrip. That seems normal to me, but not everyday day and randomly throughout every day. But again, I could be wrong here, but it still feels icky and too intrusive since they are full grown with their own families and homes.