By Oliver Jones
May 05, 2008 12:00 PM

They are the best of friends—crashing at each other’s Hollywood homes, hanging out at hot clubs and taking holidays together at Milan’s fashion week and Le Parker Meridien Palm Springs. But if you want to know how intense the relationship between Lindsay Lohan and deejay Samantha Ronson is, ask Ashley Olsen, who struck up a conversation with Samantha, who was hanging out at Manhattan’s Beatrice Inn on April 18. “Get your 15-year-old Full House a– away from my girlfriend,” Lindsay screamed at Ashley, shocking onlookers. Why the fuss? Lindsay “saw them talking together,” says a witness. “And she wasn’t happy.”

Though neither woman has commented publicly on the exact nature of their relationship, the outburst was the latest example of how close Lindsay, 21, and Samantha, 30, have grown. After Lindsay crashed her car following a night of partying last May, which prompted her first stint in rehab, Samantha was by her side. And in the difficult months since, the pair have stayed close, going out dancing together, holding hands and sometimes even snuggling in Samantha’s deejay booth. The actress went so far as to create a Facebook page in which she called herself “Lindsay Ronson.” Some friends say the relationship has had a positive effect on Lindsay. “Sam is a good influence or at least tries to be,” says a source. “She really does want Lindsay to be [sober].”

Lindsay’s mother agrees. “Samantha is a great girl,” says Dina Lohan. “Smart, talented and a true friend to my daughter. We love her.” Others worry that the deejay keeps Lindsay connected to the nightlife and exclusive clubs that don’t exactly encourage clean living. “If Samantha’s such a good friend, she should tell Lindsay to stay home,” says a source close to the actress. “Samantha should tell her not to go out and not go to the clubs. It’s not a place where someone working on her sobriety should be.”

Still, others say Samantha has given Lindsay the one thing she needs most of all. “Sam looks out for her,” says a friend. “Lindsay’s never been happier.”