Kim Kardashian and Kanye West
Kim Kardashian straddles fiance Kanye West in raunchy video for Bound 2.

He promised fans a sexy video for his track Bound 2 and Kanye West made sure not to disappoint.

The 36-year-old rapper's fiancée Kim Kardashian is the star of the raunchy promo, which shows the couple break all sorts of taboos as they cruise down a highway.

In the four-minute clip, which premiered on Ellen, West rides through various American landscapes while making out with a topless Kardashian. At one point she straddles the rapper as they ride into the sunset.

The reality star, who gave birth to the couple's daughter in June, also reveals her 50lb drop in weight by posing in various positions in just tight trousers and a pair of high-heeled boots.

One fan of the Nick Knight video said: "I envisioned Kim when I heard it. I'm not shocked she's the whole video. If the man is in love let him scream it from the mountaintop."

Another wrote: "That video was highly sexual and extremely cringe-worthy. There is no chemistry between these two. Everything seems forced and orchestrated.

"Kim will never be known for anything other than sex and her body, and apparently that's how she and her future husband like it."

Bound 2 appears on West's latest album, Yeezus, which was released in June.

Before the big reveal West told Ellen: "[Kim's] a person that when I was at my lowest moments, I would get on the phone with her and she would make me feel like I'm here for a reason."