It's the picture that launched … well, you get the idea. Blac Chyna set social media buzzing on Monday, January 25, when she shared a picture of a heavily tattooed arm wrapped around her in a sweet embrace. "The beginning," she captioned the photo.

The arm belonged to Rob Kardashian — and soon Twitter was melting down over the unlikely new pairing.

Chyna — who was previously close friends with Kim Kardashian — used to date Tyga, 26. The two broke up in 2014, and the rapper went on to date Rob's youngest sister, Kylie Jenner. What a tangled web!

Here's what we know so far about Rob's fledgling relationship with Chyna, plus a timeline of her up-and-down history with the Kardashian clan.

June 2014: Kim and Chyna Were BFFs

Chyna documented her friendship with Kim in a selfie that showed the pair in a car, with Kim sans makeup.

July 2014: They Met Through Their Men

The pair, whose partners Kanye West and Tyga are close, also showed off their bootylicious bods in a pic Kim posted on Instagram.

August 2014: Tyga and Chyna Split

Tyga and Chyna, who began dating in 2011 and share a son, King Cairo Stevenson, 3, called it quits.

October 2014: Tyga Befriended Jenner

Jenner began popping up in Tyga's social media posts, and she posted a picture of them celebrating Halloween dressed up as Chucky and his bride.

February 2015: Amber Rose Slammed Jenner and Feuded With Khloé

Chyna's close friend and West's ex-girlfriend Amber Rose slammed Jenner in an interview, saying, "She's a baby, she needs to go to bed at 7 o'clock and relax. [Tyga] should be ashamed of himself. He has a beautiful woman and a baby and left that for a 16-year-old who just turned 17." That led to a heated Twitter battle with Khloé Kardashian, who defended her little sister.

March 2015: Jenner Threw Shade at Chyna

Hours after Chyna shared a photo showing off a diamond-covered watch, Jenner posted a pic showing the exact same watch, hinting that Tyga gave them both the same timepiece.

April 2015: Chyna Mocked Jenner's Bigger Lips 

Chyna posted a photo of herself on Twitter wearing a huge pair of red wax lips in what appeared to be a dig at the viral #KylieJennerChallenge.

September 2015: Tyga Accused Chyna of Lying About Him and Jenner

Tyga slammed Chyna on Instagram for spreading rumors that he couldn't afford the $320,000 Ferrari he gave Jenner for her 18th birthday. "When the hating don't work they start telling lies," he wrote, adding, "#WhereYoFerarriTho?"

January 25, 2016: Chyna Shared a Photo With Rob

Chyna posted a pic that showed her being embraced by a tattooed arm, and social media melted down over speculation that the ink was the same as Rob's. A source told Us Weekly that Rob is spending time with Chyna. An insider revealed that they are "seeing each other," adding, "They've been hanging out. Not sure what to call it yet, but they are hanging out. There's a romantic vibe there."

Hours later, Kris Jenner tweeted about having "a challenging day," but she was not the only member of the clan to respond to the news — Khloé shared a cryptic tweet with a quote from The Godfather that appears to be a warning: "You can do anything. But never go against the family."

Kylie also tweeted, then deleted, a message hinting at trouble with her brother, and Tyga alluded to the surprising news on Snapchat, posting a video with "Inside the Mattress" by Future playing in the background.

January 26, 2016: Rob's Family 'Is in a Bind' Over His New Relationship

Rob added fuel to the fire by reposting a meme on Instagram that featured a paparazzi pic of Chyna carrying a car seat along with the caption, "Blac Chyna probably out shopping rite now as she plan to give birth to the only next generation of the Kardashian Name! #BabyKardashian."

A source told Us the family is torn over Rob's new relationship: "The family is in a bind trying to be supportive of Rob's life while being sensitive of Kylie's relationship with Tyga."

Want stories like these delivered straight to your inbox? Sign up now for the Us Weekly newsletter!