Inside Miley Cyrus & Kaitlynn Carter's Steamy Romance - The Real Deal Or Just A #HotGirlSummer Fling?

Miley Cyrus and Kaitlynn Carter are making the most of their #HotGirlSummer!

As we reported, fans were shocked over the weekend when photos of the two bikini-clad babes sucking face in Italy were released just a week after Carter called it quits with Brody Jenner — and mere hours after it was announced the Mother’s Daughter singer had split from husband Liam Hemsworth.

The PDA-filled poolside pics triggered a bit of back and forth between Miley and Brody on social media, leaving fans wondering exactly when the hooking up began — and more importantly…

How did these two even meet in the first place?!

Well, according to an ET source, Miley and Kait actually met through Liam and Brody (!!), as the former couples reportedly spent time together as a foursome (so to speak) before their respective breakups!

The insider claimed:

“The [ex] couples are friends — the four of them have spent time together in Malibu. Brody and Liam are both into surfing and are friends.”

Whoa!

No wonder Brody’s been so vocal about Miley and Kait’s hookup on social media: he basically introduced them to each other!

A second source told the outlet The Hills star’s ex has always been fond of the pop star — and while they’ve apparently known each other for “several months” now, the “hooking up” aspect of their friendship is “very new”!

The second insider claimed while none of the A-lister’s friends believe her new fling will last longer than a standard #HotGirlSummer, both the songstress and the blogger are very much enjoying their time together:

“For Miley, she’s having fun, and for Kaitlynn, it seems too coincidental that she is hooking up with a huge music star, when that’s what she wants most for herself in life — to be famous.”

LOLz… gotta love when sources throw shade!

A third source told the publication Miley and Liam still “love each other and always will,” and most of their friends believe “they’ll be back together.” That insider explained:

“No one thinks Miley and Kaitlynn are in a real relationship, they believe it’s more fun on vacation… Liam loves Miley and is hurt, but he knows that she does this.”

Apparently, the pop star’s #HotGirlSummer was inevitable, as the source claimed Liam is “not surprised” by her steamy outing with Brody’s ex:

“Miley and Liam very recently separated. Miley’s behavior is no shock to Liam. He is hurt but not surprised. The last several months they’ve been talking about taking a break. Liam’s been frustrated with some of her antics and in turn, Miley claims she ‘needs her space.’ This seems to be a pattern in their relationship.”

Hmmm. Sounds like this split was a long time coming.

The question is: will Miley and Liam rekindle their romance once she’s done riding the waves of her HGS?