Do you always know where they are, and if not do they tell you? E.g would it bother you if they had stopped off to see friend/family on their way back from work and then came home and never mentioned it and you only found out when the friend/family member mentioned it to you in passing? Do you know what they spend their money on and how much they spend and do you ever ask if you see them with something new? Do you have individual savings or shared? Do they share private information relating to their friends and family?
Very bizarre question I know, and I have no doubt it varies person to person, but I've been raised seeing an extremely dysfunctional relationship through my parents, and I'm trying to ascertain what is healthy/the norm and what is controlling/overbearing.