Both Lex and Jason were clearly too young to remember their early friendship, as they introduced themselves to each other at Lana Lang's bedside when she was admitted to hospital. Jason and Lex were civil to each other, although Lex was suspicious of Jason's relationship with Lana.
Jason was very respectful of Lex, as he provided the new jerseys for Jason's football team. However, after receiving confirmation of Jason's affair with Lana from Clark Kent, Lex had Jason fired, although he remained anonymous. Lex claimed to feel guilty about this and called Jason in to LuthorCorp for a job interview. However, before the interview could take place, Jason was infected with a hallucinogenic toxin that leaked out from LuthorCorp and caused him to live his worst fear. Although he recovered, this only damaged his relationship with Lex further.
Lex encouraged Jason to come back in order to build up a constructive relationship, at the request of Jason's mother, Genevieve Teague. While Lex gave Jason the impression that he trusted him by sharing theories about Jason's estranged mother, Lex remained suspicious and warned Lana that he might be using her. Lex's father, Lionel Luthor interfered with Lex and Jason's alliance by warning Jason that Lex was not to be trusted and gave him a copy of Lex's map, which caused the decline in their relationship.
After this, Jason decided to pursue the stones alone by following Lex's manuscript to China. Jason was frustrated when he discovered that Lex had followed him there but they were forced to work as a team again when they are chased by police. Jason was concerned for Lex when he was dragged off for interrogation, but Lex was merely manipulating Jason again and had in fact employed the torturers to force Jason to reveal everything he knew about the stones. Nevertheless, Lex was keen for them to not hurt Jason, indicating that, although he didn't trust him, Lex did not want Jason to come to any harm.
Lex was right not to trust Jason, as when he found the Crystal of Air he kept it hidden for Lex. When Lex eventually discovered that Jason had the stone, he was shocked that he had been double-crossed. Jason continued to cause problems for Lex when Jason dumped the body of Virgil Swann's assistant, Bridgette Crosby, on the grounds of the Luthor Mansion framing Lex for murder. Jason threatened to tell the authorities about the body if Lex didn't tell him about an artifact that had been mentioned in an email between Brigette and Lex. This destroyed any chance of an amicable relationship between the two, although Lex remained unconcerned by Jason's threats, as he had dealt with the body, unaware that he had been manipulated by Jason, as that was his plan all along.
Despite their similar manipulative nature, their lack of trust in each other, led them to become full blown enemies. Jason and Genevieve united against the Luthors by kidnapping Lionel and Lex to force them to hand over the remaining stones. By now, Jason had no concern for Lex's wellbeing and was fully prepared to torture him. It was only when Lionel revealed that Lana had the stone that they stopped torturing Lex.
While Genevieve went to collect the stone, Lionel and Lex tried to appeal to Jason's better nature and when he let his guard down they made their escape. Lex had clearly built up a deep resentment of Jason, as he attacked him to reclaim his freedom. When Lex cornered Jason on a cliff's edge, Jason tried to reason with Lex but Lionel shot him, causing Jason to fall off the cliff.
Lex later visited the Kent Farm and disposed of Jason's body. He then confirmed that Jason and Genevieve had died in the second meteor shower in the newspaper. Lana read the article and saw a note from Lex remembering that she already owed him a favor.
|Lex Luthor in Smallville|