Jenner, 30, and the TransWorld Surf's Miss September 2012 had a brief four-month romance. Us confirmed in late June that the two began dating. "It just fizzled," the insider says of the breakup.
The Hills alum and the gorgeous blonde first debuted as a couple when they stepped out in Malibu, Calif. on July 6. The pair kept a low profile during the outing, with the reality star dressed in black shorts, flip flops, a white t-shirt and hat. Holly, meanwhile, wore tight-fitted jean shorts, a white tank top and sandals.
Jenner previously dated Avril Lavigne before Holly. The rocker tied the knot with Nickelback frontman Chad Kroeger in the South of France in July.
Bruce Jenner's son has also been linked to Hills alums Lauren Conrad and Kristin Cavallari. The Paper Crown fashion designer revealed in mid-October she's engaged to Something Corporate singer turned law student William Tell. Cavallari announced late last month she's expecting her second child with husband Jay Cutler.