The Twilight stars ended their on-off relationship earlier this year, so when Rob was spotted pulling up to K-Stew's home in Los Angeles on Monday (5 August), speculation immediately began that the pair had rekindled their romance.
But before Twilight shippers get too excited, according to E! Online Kristen wasn't actually there when Rob arrived.
The purpose of Rob's visit is unclear but we can think of a few reasons why he'd need to visit his ex's house: Collect belongings? Say hello to the pets?
Whatever the reason, Kristen probably didn't mind as a source has told Us Weekly that the former couple "stayed friends and have always kept in touch".
Kristen and British-born Rob began dating after working together on the first Twilight movie, which was released in 2008.
They enjoyed an on-off relationship for the next four years and always kept their personal lives private - until Kristen was forced to admit to an affair with a married film director last year.
A magazine in the US published photos of Kristen kissing her Snow White and the Huntsman filmmaker Rupert Sanders, who was married to model Liberty Ross at the time.
Kristen issued a public apology and the couple appeared to put the indiscretion behind them until May of this year when they broke up again and Rob moved his belongings out of their home.
Will they get back together? We honestly wouldn't be surprised...
But in the meantime Rob has been linked to Elvis Presley's granddaughter Riley Keough, a mystery woman he was allegedly seen kissing in Canada, and even Katy Perry, although the latter has denied a romance.
Katy told the new issue of ELLE magazine that she reached out to Kristen after hearing the rumours, saying: "I sent her a text message saying: "I know you've seen all this stuff but you know I would never disrespect you. I'm not that person. I'm just trying to be a friend to him but it is unfortunate that I do have a set of tits."