Samantha Ronson and her rumored girlfriend Lindsay Lohan snubbed her own birthday celebrations on Tuesday night - reportedly abandoning the party to avoid photographers.

Ronson and her twin sister Charlotte threw a double celebration in honour of their 31st birthdays at the Bowery Hotel in Los Angeles.

But the pair were said to have left the party early after a swarm of photographers arrived outside.

A source tells New York Post gossip column PageSix, "Charlotte and Sam do this party every year with (publicist) Amanda Silverman."

"The photographers must have caught on because they were outside the hotel. Sam and Lindsay were livid and just left to go do their own thing."