According to Soap Central, Kristen DiMera started off as one of Salem's nice girls. She was a social worker, and Alice Horton even hired her to work at the Horton Center. However, Kristen was harboring a secret. She had been taken in by none other than notorious Salem villain Stefano DiMera (then Joseph Mascolo). She began to consider Stefano a father figure and even helped him go into hiding while he was suffering from a brain tumor. John Black was very upset when he learned about Kristen's strong connection to Stefano. However, he couldn't deny his love for her. Sadly, John and Kristen couldn't be together, as she had promised Stefano on his deathbed that she would marry his son Tony DiMera.
When Kristen thought that Stefano was dead, she went through with her marriage to Tony. However, she was shocked when she discovered that her adopted father was still alive. This revelation sent her straight back into John's arms, despite being married to another man. Kristen eventually left Tony, but she and John couldn't be together because he had become a priest.
Also, it was clear that John still had feelings for Marlena Evans (Deidre Hall). When Marlena became possessed by the devil, it was John that performed the exorcism that helped save her life (via Soaps in Depth). After that, Kristen's life took a huge turn, and she truly embraced the DiMera name.
