No such thing as a curfew. If we live/sleep together I would hope she would just hit me and let me know if she’s coming home tonight or not. I give a see y’a later and that’s what I plan on doing. Just mutual respect.
Time does fly when you are out though. But I think you know the type of partner you have. If they are loose people then I can see it. If you know they get side tracked then just know they must be having a good time.