Saw something on another thread that made me think how lovely it must be to go to your parents house and still feel it is home.
Although we are close, I have quite a formal relationship with my DM and step dad. I don't have a house key, when I visit them I ring the doorbell and wait for them to answer the door, even if I can see them through the window. My old bedroom has been turned into a room for one of my siblings (he lives an hour away) and the box room is now a bedroom for his dd. None of the other dgc have ever spent a night in their house.
Weirdly I feel much more comfortable in DHs family home.