I have a deep ethical question for anybody bored enough to answer. Today my apparently-single-big-gummed-female-allergic-to-cats neighbor came over today to ask me if the black cat that was sleeping on her couch today was mine. (It was) She has this terrible little dog, I can only assume its small by the tone of its incessant barking, that needs a doggie door. Apparently this doggie door is open during the day. Here's my ethical/moral question. Is it my responsibility to keep my cat inside all day so that he doesn't sneak into my neighbors house or is it her responsibility to keep her doggie door shut during the day?