This week on the CW's Smallville (Thursdays at 8 pm/ET), Lana Lang (played by Kristen Kreuk) walks back into Clark's life, and at a most inopportune time — at least as far as Lois is concerned. "[Lois and Clark] are both discovering how and what they feel," Erica Durance previews in this video. "There is a moment when you think that they may actually admit that to each other... and then Lana comes back."

Ms. Lang, of course, is not some everyday high-school flame to be casually dismissed. As Durance notes, "The writers did a lovely job of creating this amazing first love relationship for Clark... and you can't take that away. What I worked really hard with the writers to portray is that Lois is sensitive to that."

So even though "Lois is a fighter... she realizes that sometimes you need to be patient," Durance says. The actress then adds, "We all know [Clark and Lois] end up together, but the joy is watching the journey. The more selfless Lois is with her love for Clark, the more she'll deserve him."

Watch the full video below.

ALSO: Watch clips from this week's "Bride" episode here, here and here.