Paris Hilton has recently dropped her newest music video for her single "Best Friend's A**" and it only seemed fitting to have her BFF, Kim Kardashian, cameo in it.

Since May, the two socialites have been in the headlines after an Instagram post that revealed the pair were putting their heads together and working on a top secret project of theirs.

People have been speculating about this secret project. And fans have even gone so far as to theorize that they were collaborating on a makeup line together. Which is not really that far-fetched, seeing as both of them have been in the business of launching and marketing their self-made cosmetic brands.

The BFFs were also recently spotted together on the set of a music video and were in matching silver mini-dress ensembles, much like Hilton's iconic dress, the one she wore to her 21st birthday party. That get-up had been so popular, it has since been coveted and copied by socialites and actresses everywhere.

Nonetheless, now the secret is out, and so is Hilton's new music video for "Best Friend's A**" which features no other than Kardashian, who eerily fits in with the whole theme and lyrics of the pop tune.

Hilton and Kardashian go way back. Before Kardashian was launched into fame and became a household name, Hilton was the "it" girl of the era. Dresses she wore sold out immediately in boutiques; paparazzi mobs hounded her everywhere she went, and her mere presence in a room commanded attention.

Eagerly at her heels, Kardashian was slowly getting what little exposure she had from being Hilton's best friend back in the day. And then it seems Hilton's 15 minutes of fame were up, and Kardashian was basking in the spotlight she loved.

As time wore on, the two grew apart and took separate paths, in pursuit of their individual careers. And now it seems that they have rekindled their old friendship and are both starring in a music video about their younger days which they spent clubbing.

However, fans seem a bit surprised at how the music video turned out. Kardashian is only seen for three- to five-second intervals and overall just twice in the video. It did turn out the way they had expected.

Naturally, considering the single's title, people have assumed that the famous Kardashian's behind would be highlighted in the video. But the reality star is only seen from the waist up, clad in one of those silver mini-dresses.

Hilton's single is a new track with modern feels to it; however, it transports fans back to a time of an old friendship, but one between two people who have long since changed.