Deleted Scene From Injustice

Shortly after her reported death, Lana was seen alive in hiding in Shanghai, China wearing a blond wig. No one was aware of her faked death until Lex found her in Shanghai. She left her clone (model 503) that Lex created in her car. When it blew up, they found her DNA. While explaining all of this, Lana held Lex at gunpoint but she was unable to kill him despite his actions. He told her she could return to Smallville and that he would take care of everything for her. Lana took his offer and returned to Smallville and meets Clark in the barn. He is shocked to see her alive and also is delighted...

First Season
"Statistical fact, Clark Kent can't get within five feet of Lana Lang without turning into a total freak show" - Chloe - Pilot

Clark has had feelings for Lana for a long time. At the beginning of the series, Lana dated Whitney Fordman and wore a kryptonite necklace, preventing Clark from coming near her without feeling its effects. Throughout season one, Clark's feelings grew for her, and a tentative friendship blossomed. Lana continued to date Whitney however.

There was tension between Clark and Whitney, and noticing their friendship, Whitney suspected Clark's feelings for Lana....