Stephen Colletti rang in his 22nd birthday without on-and-off-again fling Lauren Conrad.

The Laguna Beach alum — who once dated Hayden Panettiere — arrived solo to his bash, which kicked off at Stack restaurant at The Mirage in Las Vegas Friday before moving on to JET Nightclub.

Colletti didn’t seem to care about his single status.

Throughout the night, he threw back Red Bull and vodka cocktails and “got very chatty with a slew of sexy ladies,” says one club-goer. “He spent most of the night dancing as each [woman] patiently waited her turn to groove with the eligible bachelor.”

Colletti took a breather midway through the night to blow out candles on his cake by designer Jean-Philippe Patisserie before hitting the dance floor.

He called it a night around 3 a.m.

Though she’s been spotted making out with Colletti, Conrad recently told Usmagazine.com, “We’re just friends.”

Source, WENN