Paris Hilton and her new man, The Hills star Doug Rheinhardt showed off their new-found 'love' this weekend at the heiress' birthday celebration in Las Vegas.

The socialite jetted 20 friends - including Doug - to Bright Light City to celebrate Paris turning 28 two weeks ago on February 17.

The heiress and her entourage arrived at the Hard Rock Hotel on Saturday, dressed up to the nines, before heading to Nobu for dinner and rounding off the night at a private party in the hotel's Body English nightclub.

During the evening Lauren Conrad's ex-boyfriend made a toast "to the world's prettiest girl" before locking lips with Paris until the evening came to a close.

The Sun reports that Paris dedicated a rendition of Stars Are Blind to her new man before telling the crowd: "My man is right over there, the sexiest man in the world."

Two weeks ago, Paris celebrated her birthday twice over in New York with a stylish celebration at swanky club/restaurant Butter before following up her soiree with another party one week later at My House.

See Paris' Frocky Horror Show below