Jason and Lex played together while they were children alongside Patricia Swann and Oliver Queen, whilst their parents discussed their secret society of Veritas. Lex had apparently first met Lana when she was ten and he was sixteen. She had walked in on him skinny dipping with Patricia Swann after Lionel Luthor had invited her and her aunt to stay with him during a riding competition. Years later Lex moved to Lana's hometown of Smallville, they met again during a farmer's market. The two then became friends through their mutual friend of Clark Kent. Lana made a big impression on Lex and he did not take long to discover why his new friend Clark was interested in her. Lex would always try to give Clark tips on how to win Lana over but he rarely acted on them. Later Lana convinced Lex to reopen the Talon and turn it into a coffee shop thus beginning their buisness partnership. Lana could not help but notice that Lex was also interested in her and when she was infected with the Nicodemus flower, she tried to take advantage of this situation and tried to seduce Lex to get what she wanted. After Lana was cured they continued their usual relationship as if nothing happened. Lana planned to study aboard in Paris and Lex paid for her trip to Paris and on the day she left he was the only one to say goodbye to her at the airport.
Season FourIn Paris, Lana met and began a relationship with Jason and spent the entire summer with him. Lana however felt as if something was calling her back to Smallville so she returned there. There she met with Lex and they both happy to see one another. Lex could tell that Lana had changed during her time in Paris. Lana was admitted to the hospital and both Lex and Jason were at her bedside and clearly too young to remember their early friendship, as they introduced themselves to each other. Jason and Lex were civil to each other, although Lex was suspicious of Jason's relationship with Lana, as he correctly guessed they had more than just a student/teacher relationship and also stated that Lana deserved the best hoped that Jason was it for her.
Lex received confirmation of Lana and Jason's affair from Clark and had Jason fired from Smallville High where he worked as an assitant football couch, although Lex remained anonymous. Clark confronted about the situation Lex and he defended his actions saying their relationship was inappropriate. Clark went on to say that the whole town was talking about Lana and doubted Lex did it for moral purposes. Clark questioned Lex's motivation, but Lex didn't give him an answer.
Lex later went to see Lana at her apartment at the Talon and explained to Lana that he was the one to get Jason fired and not Clark. Lex stated that he had only her best interest in mind but Lana wildly defended her relationship with Jason and said she was old enough to decide who she wanted and didn't want in her life.Lex claimed to have felt guilty about getting Jason fired from the school so Lex called him in from a job interview at LuthorCorp. Jason however did not tell Lana about it. Jason later ended up getting sick from a fear toxin accidently released by LuthorCorp and fell into a coma. Lex then learned that Lana was suffering from the same toxin and worked hard to cure them both of the deadly toxin. After Lana and Jason were both cured, Lana asked Jason why he didn't tell her about the job interview at LuthorCorp but Jason didn't to leave because he said he didn't like who he was becoming.
Jason questioned Lex's intial job offer as he did not like the fact that Lex was trying to break him up with Lana. Lex said to Jason that his true threat was his mother and said that she had been researching about her ancestry which ties with Lana and her being possessed by a former ancestor, Countess Margaret Isobel Thoreaux. Lex tried to convince Jason that Genevieve maybe the cause for the Countess's possession of Lana and instructed him to learn how much Genevieve and Lana know about the Countess. Jason was convinced but did not like the fact that he would have to spy on both his mother and his girlfriend about their ancestrally intimate bonds. Lana was later furious that Jason accepted Lex's job offer. Jason told her he would use this to get to more information about Lex as well as for his and Lana's research on the Countess. Lana feared that taking this job would be Lex and Genevieve's way of breaking them up. Jason told Lana to trust him and she decides to see Lex for herself, to which she expressed her angry for hiring Jason to learn about her. Lex later met with Lana and informed her on how Jason was brought up knowing about the Countess which caused Lana to reevaluate how well she knew Jason.
Lana was surprised to learn from Lionel that Jason and Lex were in China looking for one of the stones. Lionel went on to tell her that they had been seriously investigating Isobel, whose arch rival was a duchess by the name of Gertrude. Gertrude was obsessed with finding three mythical stones of knowledge, but she searched the globe in vain. She was only able to find a map of a temple in China, which Isobel stole. Gertrude had Isobel executed for this. Lionel then revealed to Lana that Jason was a direct descendant of Gertrude. Lana was stunned that Jason lied to her and that he and Lex are working together behind her back. Lana then decided to go to China as well and Clark went along with her. Meanwhile in China, Lex and Jason ended up getting arrested and tossed in jail by local police and while there Lex warned Jason that he may to protect Lana from him. Lex and Jason are then both taken into interrogation for the stones and tortured. The soldiers continued to torture Jason and Lex, who were then both stunned when they brought in Lana and started shocking her. The pain unleashed Isobel, who fried the guards, brook free, and revealed that the map that Lex and Jason were using to find the stone was a key. Isobel then made threats to both Jason and Lex before going off to find the stone herself. Clark then rescued Jason and Lex and afterwards they went to look for the stone and Lana. In the events following Isobel found the stone and her and Clark battled for it and when Isobel touched the stone with her bare hand it freed Lana from her control. Jason then revealed to Lana once they got back from China and he grabbed the stone before Clark or Lex saw him and give it to her.
Lana and Jason are returned from a jog to the Talon apartment to find that it had been broken into, but the only thing stolen was the stone. Lana convinced Jason to forget about the stone, saying whoever took it can keep it. She told him that she was tired of their relationship revolving around the Stones and secrets and Jason agreed to drop the subject. However, later, Jason went to the Luthor Mansion and accused Lionel of stealing the stone, who then informed Lex that Jason had the stone and was shocked. Its later revealed it was Lana who "stole" the stone and hide from both Jason and the Luthors.
Lex finally revealed his true feelings for Lana when he was split by black kryptonite and his evil half, Alexander went and hitted on her at her apartment. He told her she deserved better than Jason. He then kissed her and told her she could be his queen. Lana slapped him and ordered him out. Alexander then told her that he was going to close the Talon if she didn't move in with him. Alexander was rebonded with Lex and Lex later apologized to Lana.Jason and Genevieve resorted to kidnapping both Lex and Lionel in order to get the remaining stones. They began to torture Lex with a hot poker and threatened to take out an eye if Lionel didn't give up the stone he "stole" from them. Lionel revealed that Lana had the stone and that she was the "Chosen One." Genevieve appealed to Jason to let her get the stone from Lana, but Lionel warned not to underestimate Lana due to her connection to Isobel. Lionel worked on Jason to turn him against Genevieve by appealing to his feelings about Lana. Jason was torn between shooting him and going to get Lana and stormed out. Lex and Lionel then managed to get free and flee with Jason in pursuit. Jason got ahead of them and a near shot sent Lionel tumbling, but Lex got the drop on him and said to him he knew he had to protect Lana from as Jason fleed to the edge of a cliff over a river. As Lex was about to send Jason down the cliff, Jason tried to appeal to Lex with Clark's involvement in all the mysterious events but Lionel shot him before he could say anything and he fell into the water below. Lex didn't trust Lionel and warned him that if anything happened to Lana there would be hell to pay.
Lex walked in on Lana immediately after Isobel killed Genevieve left Lana's body. Lex convinced Lana that it was self-defense and that she had no choice. Lana worried about what would Jason think and Lex said he would deal with Jason and offered Lana one of the best defense attorneys in the nation. He than told her to stay in the Mansion and talk to no one until the lawyer arrived. Lionel went to her apartment and had Genevieve's body taken away. He threatened Lex by saying that if he did not get the stone from Lana by noon, Genevieve's body and evidence against Lana would be given to the sheriff. Lex tried to get the stone from Lana but she had given it to Clark. As Lana was able to board a holicopter Lex demanded for the stone and searched through her purse to find it gone. Lana boarded the holicopter angry that Lex just wanted the stone from her and as did Jason.
Lex later disposed of Jason's dead body while at the Kent Farm. Jason's death was confirmed in the newspaper after the second meteor shower. As Lana read it, she expressed no remorse at the loss of her boyfriend. Next to the article was a note of Lex reminding she already owed him a favor, as she had become convinced that Jason had only pursued a relationship with her in order to help him find the stones.