Heidi Montage Celebrates 25th Birthday, Looks Much Older (PHOTOS)

Reality star Heidi Montag is famous for her on-off relationship with husband Spencer Pratt, her appearance in The Hills and particularly for the excessive amount of plastic surgery she's had.

It's hard to believe that the once fresh-faced star is only celebrating her 25th birthday, but that's exactly what she did over the weekend at a party in Las Vegas.

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