Why does Lana marry Lex?

Answer 1

It's not exactly clear.... She says she married him because she loved him but I think she was unconsciously trying to hurt Clark. However, right before the wedding Lana was going to leave Lex so she could be with Clark. But Lionel threatened to kill Clark if she didn't. Later, Lana finds out that Lionel had her marry Lex so she could get inside information to help protect Clark. Lana marries Lex in the sixth season, episode "Promise." In the season finale, Lana leaves Lex . This is because she realized she didn't love him. She even tells Lex that "he isn't capable of love." She realized this earlier, when she finds out that Lex had her injected with a certain drug. The drug made her think she was pregnant (stopped her period, nausea, etc. !signs of pregnancy) Hint! Hint! She was pregnant she kinda had to marry him. Later, when Lex stopped giving her the drug it looked like she had a miscarriage. So yeah, I think she was just dating him as a jab to Clark. And than, got rushed into the marriage because of the "baby." I don't think her relationship was going anywhere with Lex. (Lex probably knew that to, that's why he faked her pregnancy)

Answer 2

On the series Smallville, Lana did briefly marry Lex.