They really should be wearing helmets. Kanye West premieres his "Bound 2" video on the Ellen DeGeneres Show on Tuesday, Nov. 19, with the much-anticipated clip first debuting online -- and, as first revealed by Us Weekly, the romantic-raunchy rap stars none other West's famous fiancee, Kim Kardashian.

Making like a modern-day Tawny Kitaen (Whitesnake's video vixen), the reality superstar, 33, appears topless (though bathed in modest shadow) as she slithers atop a motorcycle. At various points in the desert-highway-themed clip, North West's blonde, slimmed-down mama hangs out on the parked bike -- and, later, straddles and makes out with West, 36, as he simulates riding the hog through the desert landscape.

On Monday, a close source teased Us that the "Bound 2" clip, directed by Nick Knight, would indeed by "really sexy . . . . Kim looks beyond gorgeous. It's very artsy, very beautiful. The imagery is very colorful and light. Nothing about it feels pop or urban. She looks incredible."

Watch the clip now and tell Us: What do you think?