After publicly falling out years ago, Paris Hilton and Kim Kardashian are now in a really good place.

“I’ve known her my whole life and we’ve been having so much fun together lately,” Hilton, 38, tells PEOPLE of her friendship with the Keeping Up with the Kardashians star, 38.

“We had a good time at Kourtney [Kardashian]‘s birthday party and then had fun at Travis [Scott]‘s birthday party. It’s been really nice,” Hilton adds.

Hilton and Kardashian were inseparable in the mid-2000s, posing for paparazzi and hitting the club scene together. Reality TV fans will even remember Kardashian’s first appearances on Hilton’s show The Simple Life, organizing the heiress’ closet and occasionally taking care of Hilton’s chihuahua, Tinkerbell.

But then the pair’s relationship soured and their feud saw the pals exchanging barbs in the media. Clearly, that is now all in the past, and the stars are now not only back to being besties — they are also helping to support each other’s creative endeavors.

The famous heiress recently paid homage to her reality star bestie in her new song “Best Friend’s Ass,” which was released on May 10.

“All I see is f— boys everywhere trying to make a pass but I can’t stop looking at my best friend’s ass,” Hilton sings on the dance-worthy track.

Hilton tells PEOPLE she wanted the track to be “a summer anthem for girls who rule the night and have fun. Not caring about boys and all about your best friend.”

“When you listen to the lyrics it’s hilarious. I sent the song to Kim and she loved it,” Hilton says. “With a title like that, I, of course, had to have her in it.”

Hilton posted a series of Instagrams to promote the song, including two with Kardashian, who will make an appearance in the upcoming music video.

“It’s these two girls who are going in the club and as soon as they put on these Instagram Goggles they go into an alternate universe and it’s this perfect world,” Hilton says of the video.

“We went to Nightingale. It’s just a really fun night. Just basically showing reality versus the fake social media world. It looks like the most amazing party.”

Source: people.com