Partner and I recently bought a house so we could live together. Her eldest is 17 and the handover is on a Friday night. I enjoy having this routine and structure and as much as I adore her kids, I love my Friday evenings just with my partner.
Occasionally he asks if he can stay an extra night, for example if he wants to go out into town. I wouldn't mind, but she agrees without asking me first.
Am I being unreasonable in thinking it would be polite to ask me as a courtesy? I wouldn't dream of saying no and I'm pretty sure she knows that.