10 Most Inappropriate Superman Storylines
5. Superman Marries Supergirl
It is surprising how often the writers of Superman and Supergirl titles have tried to find a way for them to be in a romance or even get married. It’s not as frequent a troupe as Lois finding herself in some strange predicament because of her trying to make Superman fall in love with her, but the fact that it happened more than once is somewhat unsettling.
One of Superman's creators wrote a story in Action Comics #289 where Supergirl tries to set her cousin up with the most beautiful women in history. She finds a super-powered woman on another planet for Superman who is a slightly older but otherwise identical twin to her. Kal-El tells Kara that the only reason he won’t marry her is that it was illegal on Krypton.
More recently, Peter David had the current Linda Lee Supergirl travel back in time and take Kara Zor-El’s place on Earth-One so Kara won’t die in the Crisis. Superman realizes that she isn’t his cousin, they fall in love and have a daughter. However, despite her plans, Linda isn’t powerful enough and Kara has to face the Anti-Monitor. Having failed, she leaves Clark a letter and disappeared.