Kim Kardashian Wears Low-Cut Sexy Dress at Kanye West’s Cannes Film Premiere

Kanye West and Kim Kardashian attend the "Cruel Summer" presentation during 65th Annual Cannes Film Festival on May 23, 2012.  Mike Marsland/

Cruel Summer, cute couple!

Kim Kardashian was the best plus-one ever for beau Kanye West at Wednesday's Cannes Film Festival premiere of Cruel Summer, the rapper's new art film/art installation.

The reality star, 31, wore a jaw-dropping gold-and-cream Balmain dress with a plunging neckline and super-short hem, paired with sexy ankle boots. (The frock has already been worn by Katy Perry, Zoe Saldana and other stars.) West, 34, complemented his love of nearly three months in a white shirt, cream jacket, denim and black loafers.

According to a source, the couple "were inseparable" at the afterparty for Cruel Summer, one of the first projects of West's Donda creative firm. The twosome were "kissing in the back the whole time." (West's buddy Jay-Z, sans wife Beyonce, showed up to support his frequent collaborator.)

On Thursday afternoon, Kanye and Kim hit Nikki Beach La Plage with a group of ten–though an onlooker says they "only spoke to each other."

"They kissed!" the witness shared. "He was hugging her from behind with two protective arms around her waist . . . They looked totally in love."

Earlier this week, Kardashian told Us Weekly that she's having a blast while in Europe for the star-studded film fest. "It's my first time to Cannes and it's amazing! I love it here!"

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