Petra Nemcova and James Blunt are over, PEOPLE has confirmed.

"They split in February. It's very amicable," a source close to Blunt tells PEOPLE.

A rep for Nemcova had no comment.

The model, 27, and the "You're Beautiful" singer, 32, were last seen together over Oscar week in February, when they hit a slew of parties. They celebrated his birthday and also went to Elton's John's Oscar bash, where Blunt performed and Nemcova looked on.

But in recent weeks, Blunt has become a regular fixture in the Hollywood nightlife scene, hitting the town solo. He was spotted on the same night – March 21 – at both Les Deux, where he hung with pal Robbie Williams, and later at Teddy's, where he partied with Lindsay Lohan, Kelly Osbourne and Amy Winehouse.

According to a clubgoer at Teddy's, "Lindsay and James were never affectionate, but they did seem flirty, standing right next to each other, and constantly talking." Lohan and Blunt were part of a group of people who left together at 2:15 a.m.

Nemcova and Blunt met in December 2005 and started dating the following year. In November 2006, rumors circulated that they'd split, but the couple denied the stories.

"We never got separated," Nemcova told PEOPLE at the time. "There was some stuff going on in the press, but it didn't come from a right source – obviously. We're very much in love."

Blunt was the Czech model's first serious relationship since her longtime beau, photographer Simon Atlee, died in Thailand in the 2004 tsunami. (Nemcova survived by clinging to a palm tree for eight hours, and suffered a broken pelvis.)

Blunt was recently in the news when police said he was involved in a car accident outside a pre-Oscar party in which a man's foot was run over. Blunt's rep says the singer was steering through a crowd of paparazzi.