Lindsay Lohan is engaged, it has been reported.The 21-year-old star, who has been pictured sporting an engagement ring, happily accepted new love Riley Giles' proposal of marriage, says her bodyguard. Lindsay, who met Riley during her recent two-month stay in Utah's Cirque Lodge rehab clinic, was seen buying a new ring at a Los Angeles boutique yesterday. While Lindsay refused to answer questions about her engagement, her bodyguard decided to speak for her, offering a resounding "yeah".The 'Mean Girls' actress has already been seen wearing a Cartier ring on her wedding finger over the last few days. However, Lindsay's representatives have denied she is engaged, claiming the Cartier ring was a present from her father Michael which she has had for some time. She has now moved the ring to her middle finger.Lindsay has made no secret of her strong feelings for the professional snowboarder. She recently said: "I love his attitude to my Hollywood stardom. He finds it very funny and that's what I love about him. He has a good sense of humor."I know I'm back in Los Angeles and he's in Utah but we'll be able to visit each other. I can go and see him at weekends and he can come out to see me too."