Depends on the situation. Anytime that I've moved somewhere new, we've invited people over to see the place. If someone is going to be watching my place (while I'm on vacation, for example) I will also show them around. However, if I've simply invited a friend over for dinner or to hang out, then no, I don't give them a tour of my house. They will mostly see the main living area, the kitchen, and the restroom. There is no reason for them to see other parts of my house.
If I'm a guest in someone else's home, I certainly don't go giving myself a tour of their home. That's rude and an invasion of their privacy.
If I'm a guest in someone else's home, I certainly don't go giving myself a tour of their home. That's rude and an invasion of their privacy.