I routinely let myself into my in-law's; did it this morning and will do it again tonight. So having their keys on my ring make sense.<quoted text> I can understand people who carry keys to parents homes. But I don't live in the same town as mine. There is no need for me to carry that on my key ring. I only bring that if I'm headed out of town for a visit.
I leave the other two parent's keys on because I know if I ever need to use them, it will be in an emergency and I don't want to have to go hunting for them.