Lindsay Lohan and gal pal Samantha Ronson share kisses at Cannes

Lindsay Lohan planted this liplock on celebrity deejay Samantha Ronson in Cannes Thursday - fueling new rumors that the two are a lot more than just friends.

The couple held hands and smooched during a party on Sean (Diddy) Combs' yacht.

Lohan, 21, and Ronson, 30, have been followed by rumors that they've been involved in an intimate relationship for nearly a year. Both have denied it.

Asked about the coziness in Cannes, Lohan's rep, Leslie Sloan said only, "They are close friends."

Some celebrity watchers have speculated it was all just an attention-grabbing stunt by the publicity-hungry actress.

But to some who saw the two sharing a passionate kiss on the top deck of Diddy's party yacht it looked like the real thing.

"They didn't seem to care who was watching," one said, according to London's Daily Mail.

Last year, Star magazine printed lovey-dovey e-mails and text messages allegedly sent from Lohan to Ronson.

One read: "Babe, if I don't have you in my life then I should just go die... I want to marry you."

The "Mean Girls" star was spotted with a ring on her engagement-ring finger Wednesday night, but she isn't believed to be dating anyone - at least not a male - right now.

It was last May that Lohan was photographed in Hollywood apparently passed out in Ronson's car and keeled over on a nearby sidewalk.

The evening capped a wild Memorial Day weekend that saw Lohan crash her car and get busted for DUI.

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