His sister Stephanie Pratt and her motocross beau Josh Hansen "went their separate ways," her rep confirms to PEOPLE.
There are no further details about the split, but it seems that the relationship did not end on amicable terms.
"Another dysfunctional move by Stephanie pratt," Hansen Tweeted Monday. "I was under the impression u had to be someones bf in order to get dumped."
Pratt, 24, and Hansen, 26, first hit it off after meeting through Brody Jenner at a Hollywood nightclub on one of the last episodes of The Hills. The duo continued hanging out post-Hills and walked the carpet together at the show's series finale last month.
In response to Hansen's Tweet, Stephanie Tweeted, "No josh Hansen u were dumped stop acting like a child. Keep star [expletive] ur (sic) way into Hollywood. Now pls GO AWAY!!!!!!"
A rep for Hansen says the two were never an official item and that the racer is "moving on." Meanwhile, Hansen has kept himself busy by Tweeting to former Girls Next Door star Holly Madison.