I think that informing someone you live with about the basics of your general whereabouts in terms of leaving, returning home, on a "date", is common courtesy. Some see it as their partner trying to "control" them and don't feel they should have to "answer" to anyone. My thought>>>>GROW UP!
My former poly partner and his other partner were in disagreement about this whole issue. She didn't feel she should have to tell him about when, where, with whom, etc. When he would ask, she saw it as him trying to control her. (They lived together. He and I didn't.) Considering that she has a 9 year old son that he often provides care for/co-parents....I really think that providing this basic information would be important particularly in case there was an emergency.
When my adult son and I lived together for a year I let him know if I was going to be out, the general area, on a date, etc. He did the same in return. It was providing information....not getting "permission".