Robert Pattinson and Kristen Stewart

The on/off couple have apparently called time on their four-year relationship, and it is said the 'On The Road' actress is finding it tough to deal with.

A source told HollywoodLife.com: "They are basically allowed to date other people and Kristen is super sad over the whole thing.

"She has absolutely no desire to date anyone and the thought of Rob possibly seeing other people has made her sick to her stomach. She's depressed and rightly so.

"Her good friends have been hanging out with her at her house giving her support. This is a tough time for both of them. But Kristen seems to be taking the split the hardest."

The 'Twilight Saga' stars first broke up for two months last summer after the actress' fling with director Rupert Sanders, and it is said the affair could be the reason for this recent break.

An insider told Us Weekly: "All this stuff came up. A lot of issues came up. [They argued] about the cheating, about how selfish she always is, about how moody she always is."

Meanwhile, Robert was looking "miserable" on Sunday when he was reportedly spotted moving his belongings out of Kristen's home.

Speaking to Life & Style magazine, a source revealed: "[He was in there] for maybe 30 minutes.

"When he came out, the back of the truck was loaded with stuff. Suitcases, a bike, trash bags full of his things.

"[He] looked miserable ... He looked like a man who had just been kicked out."