Mpreg
The short term for male-pregnancy. Usually seen in fanfiction and fanart work.

Best damn stuff I ever came across and very good to read when you are not in a good mood.

Common fandoms for mpreg include: Harry Potter, Naruto, Hetalia, Bleach, Glee, Super Natural and Kingdom of Hearts.
Girl1: "whats mpreg"
Girl2: delicious~
Boy1: Some sick twisted idea made up by a woman more than likely
Girl2: sick and twisted... no no no, its wonderful and addictive
Person: Its male pregnancy...
Girl2: squeee exactly, so very kawaii
Girl1 & Boy1: You scare me sometimes...