Kourtney Kardashian is ready for her close-up!

On Sunday's all-new Kourtney and Kim Take New York, the reality star prepares to appear on ABC's long-running soap One Life to Live's March 28 episode.

In the above clip, she practices her lines with sis Kim and beau Scott Disick before meeting the rest of the cast. "It's like I'm watching Brad Pitt and Tom Cruise," Disick jokes as the girls recite Kourtney's scenes.

"I literally thought I would have two lines and my script is so long," Kourtney, 31, admits. "I have to kiss a guy, but I'm not an actress. I just don't feel like kissing some random guy. This is definitely a lot more than I thought I was agreeing to."

Later, the first-time actress comes face-to-face with her kissing partner, David Fumero, who plays bad boy Cristian Vega. As the pair rehearse, Kourtney -- as lawyer Kassandra Kavanaugh -- gets flustered. "I don't know any of my lines!" she cries.

Despite her jitters, once the cameras rolled, Kourtney's costars say she was a natural actress.

"[She] nailed her lines," OLTL's Kassie DePaiva says of the star, who brought 15-month-old son Mason to the set and was in and out of the November 11 shoot in New York City in just three hours. "She's welcome back anytime!"

Catch more of Kourtney's on-set experience when Kourtney and Kim Take New York airs Sunday at 10 p.m. (EST) on E!.

By Allison Corneau for UsMagazine.com. For more Channel Surfing, click here.