Binder and Plastino conclude the introduction of Bizarro in Action 255 (Aug.59).
Lois, not being a total idiot, realizes something is wrong with the Superman proposing to her. Bizarro then winds up in battle with his own creation, for the love of Lois, who does not want either of them.
Bizarro tries to enlist Superman in the battle, but the second Bizarro dies in a cloud of kryptonite dust. The second duplication returning that weakness.
Since Lois refused him as Superman, Bizarro decides to make a play for her as Clark Kent. Superman has to act quickly to prevent him from giving away his identity.
Finally, Superman uses the imperfect duplicator on Lois Lane, creating a Bizarro Lois. The two Bizarros act as iff they were made for each other, and fly away to find their place in the universe.
Bizarro returns the following year.
Supergirl is given a mission by Superman to test her skills, as he orders her to fly to the 21st century, in this Binder and Mooney story.
Supergirl finds a space orphanage, and hnags around after repairing the dome, helping out two boys, Tommy and Jik, who remain unaware of her presence. Tommy does save Supergirl from some kryptonite, but really it was a fluke, as he had no idea she was around.
Supergirl arranges an adoption for Tommy before heading back to the present, and her orphanage. We learn that the boy became Tommy Tomorrow. So presumably he and Tim are not biological brothers.