Sports Illustrated Swim cover model Kate Upton is the latest stunner to do a risque ad for fast food chain Carl's Jr.

The model made her commercial debut last night in a new spot for the chain's Southwest Patty Melt, where she strips while sensually eating the burger.

The spot is very, very revealing ... but is it the sexiest one the company has ever done?

In the past, they've run suggestive ads with Paris Hilton, Audrina Patridge and Kim Kardashian.

Check 'em out below, then vote:

Paris's ad:

Audrina's ad:

Kim's ad:

Hot Videos