Take the following news item with a grain of salt the size of Robert Pattinson's fan base...

An unnamed source tells Perez Hilton that Nikki Reed and Kristen Stewart "can't stand each other." The reason? Robert Pattinson cheated on the latter with the former!

"Kristen has never forgiven Nikkie for the fling she had [with Rob]," this insider claims. "Kristen never confronted Rob about the affair, she just put the blame on Nikki and accused her of pursuing him."

After remaining relatively off the celebrity gossip radar for a few months, Robsten has been making ridiculous tabloid news for a couple weeks ago. One second, they're married. The next second, on the verge of a break up. It's just so hard to keep track.

Do you believe this latest rumor?

[Photos: WENN.com]