Father is visiting his son, who makes Kiddush on Friday night or vice-versa when he visits his parents home. The son is married and has a family. Who makes Kiddush in this case?
The Sulchan Aruch mentions honoring the guest to Birkat Hamazon and the landlord to Hamotzi, but he doesn't mention Kiddush. Though, if it is a guest whom the landlord has an obligation to honor, such as a father or father in law, it might be right to honor him, unless he agrees to pass it over. Rabbi Ro'i Margalit