Answer: Memoir is any nonfiction narrative writing based in the author's personal memories. Autobiography is an account of a person's life written by that person. Biography is an account of someone's life written by someone else. Memoir is something nonfictional, as for both autobiography and biography is fictional.
not my business but ima just say: i wouldn't do that if i were you. he might use it against you at some point. like say he cheats. he might use that against you.