Kristin Cavallari and Audrina Partridge both starred on The Hills, so their impromptu get-together during New York Fashion Week was a mini reunion of sorts–much to the delight of their fans.

Cavallari was touting not only her upcoming book, Balancing in Heels, she was introducing her new fashion collaboration with Chinese Laundry, too.

The ladies appeared to be the very best of friends while smiling and posing for photos on the red carpet at NYFw, but those who watched The Hills know it hasn’t always been this way.

PerezHilton.com reminds fans that Audrina Partridge and Kristin Cavallari once dated the same man–Justin Bobby–or at least they made it look like they both dated him during their time on The Hills.

Thanks for coming last night @AudrinaPatridge it was great seeing you pic.twitter.com/WwkDGIpY1f

— Kristin Cavallari (@KristinCav) September 18, 2015

That no doubt led to some very interesting chemistry between Kristin Cavallari and Audrina Partridge.

These days, Kristin Cavallari is awaiting the arrival of her third child–a baby girl–who is due to arrive in November. She and hubby Jay Cutler–a quarterback for the Chicago Bears–are naming her after a dog.

“We picked out this baby girl’s name when I was pregnant with our first,” Cavallari said during a recent interview with Cricket’s Circle. “I met a woman and her dog, and I loved her dog’s name. Funny enough, it was the name she had picked out if she had a girl, but she had boys, so she used it for her dog instead.”

While that little tidbit would have been fun fodder for the reporters at New York Fashion Week, Kristin Cavallari chose to keep that part of her life on the back burner as she caught up–albeit for a very short time–with Audrina Partridge.

Exclusive: Kristin Cavallari reunited with Audrina Patridge, plus some of #LagunaBeach pals! http://t.co/hWugyVKLro pic.twitter.com/fRlYB5f1px

— Us Weekly (@usweekly) September 18, 2015

Were you a fan of The Hills? Do you love seeing Kristina Cavallari and Audrina Partridge together again?