07/16/2008 05:12 am ET Updated May 25, 2011

Lindsay Lohan Gets Diamond Ring From Samantha Ronson For Her Birthday

Things must be getting serious between Lindsay Lohan and her rumored girlfriend Samantha Ronson -- the openly gay DJ shelled out a whopping $22k on a ring for the Mean Girls actress.

Samantha -- the sister of super-producer Mark Ronson -- reportedly splashed out the hefty amount on a Cartier diamond ring for Lindsay's 22nd birthday.

Lindsay was later seen sporting the band when she and Samantha were shopping in LA.

A source says, "Sam took Lindsay shopping to celebrate her 22nd birthday.

"Although Lindsay is the major breadwinner, Sam has her own money and is very proud.

"It's not an engagement ring - simply a token of her commitment.

"Lindsay is thrilled and she and Sam are very content."

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