"He showed up early in the morning in a big red pickup truck and was in the house for maybe 30 minutes," an eyewitness told Life & Style.
"When he came out, the back of the truck was loaded with stuff. Suitcases, a bike, trash bags full of his things."
The 27-year-old Twilight star also regained ownership of his two dogs.
"His dogs have lived with Kristen the whole time, even when she cheated -- they stayed at her house -- so it is very symbolic that he has taken them now," the magazine's insider revealed.
"Kristen has been in a terrible mood and it was obvious that things were not great with Rob," a source said.
The coup de grâce was when Kstew, 23, was AWOL for the Remember Me star's 27th birthday celebrations May 13, a development the insider dubbed "very strange."
"He had friends over at his house, but Kristen was not part of the celebration," der added.
"For the past few days, they have not spent any time together."