John and Kristen met and fell in love in 1993. She was a very nice and caring person that everyone loved, but when Stefano DiMera, her foster father, needed help to kidnap Marlena for the 1,000,000th time, he turned the sweet Kristen into an evil bitch (in 1996). Despite John's commitment towards Kristen, his love for Marlena still remained. Stefano pointed that out to Kristen and Kristen went bazook! She tried everything to keep them apart including letting Stefano kidnap Marlena. When John was sentenced to death in the winter of 1996 from the murder to Anthony (Tony) DiMera, Kristen's ex-husband, Marlena believed in his innocense, but Kristen didn't know what to believe. She knew that John and Tony weren't fond of each other and she witness the crime scene with her ears. (You see, Tony hated John because he stole Kristen, the love of his life. Since Tony kept his illness a secret and he knew he couldn't live long, he planned out his murder framing John. It all took place on Jenn & Peter's wedding night. Tony actually killed himself.) All evidence points to John and there was no proof, except a diary Tony had wrote the murder plan in. When John was taken to the gas chamber and the gas was released, Jenn and Jack found the diary and ran to stop the execution. Luckily, they were just in time, although John was somewhat unconscious. Kristen hated Marlena for playing Miss Nicey-Nicey. She knew that John loved Marlena more than her. To reinforce their relationship, Kristen wanted to have his child. Unfortunately, she miscarried and coudln't have a child anymore. She kept the miscarriage a secret and with Stefano's help, she wore a padded tummy. Stefano also hired someone to impersonate her during check-ups and so forth. This lady was Susan Banks. When the truth came out that the baby wasn't Kristen and that she is just as evil as Stefano, John hated Kristen forever. Marlena and John then reunited, but Kristen wouldn't let them have all the glory. She's still obsessed with John.
John and Marlena John Black arrived in Salem as a mysterious man with characteristics of Roman Brady, Marlena's lover and husband. Everyone thought that he was really Roman, coming back after Stefano captured him. John/Roman and Marlena's bond grew strong and they got married. When the real Roman returned, he coudln't believe that Marlena is with another man. John/Roman was actually brainwashed by Stefano. Marlena and Roman eventually talked out their problem, but Marlena's heart still remained to John. They secretly made love to each other one night and Marlena's daugther, Sami, saw them. She was so shocked that she resented her mother forever for hurting her father like this. When Marlena became borned a child, it was revealed to be John's, not Roman's. Roman coudln't stand the deceit and left Salem. Feeling guiltier than ever, both John and Marlena went their separate ways, but their love remained powerful still. He was the only one who protected her from Stefano. When Kristen's deception was revealed, so was John and Marlena's love for each other. Everyone received notice that Roman was dead and that he wrote letters to his family including Marlena. The letter for Marlena said that he forgave her and accept her wishes to be with John. With that thought, John and Marlena reunited and planned a wedding, but Roman's returning. He's not really dead and he didn't write those letters either.