Mary Jane Watson, often shortened to
M.J., is a
fictional supporting character appearing originally in
Marvel comic books and later in multiple spin-offs and dramatizations of the
Spider-Man titles as the best friend, love interest, and one-time wife (as
Mary Jane Watson-Parker) of Peter Parker, the
alter ego of
Spider-Man, after the death of
Gwen Stacy. Initially, upon her introduction, she had a friendly rivalry with Gwen for Peter's affections.