Demi Moore parties like Lindsay Lohan

She has hit headlines over the past few months with her increasingly erratic behaviour.

So the latest pictures of Demi Moore are likely to cause concern among her family and friends, as the actress was seen exhibiting some very bizarre behaviour at a party with Lenny Kravitz on Wednesday night.

The 50-year-old actress played up to the photographers present at the Chanel Beachside Barbecue held at Soho Beach House Miami, leaving friends including Kravitz and George Clooney's girlfriend Stacy Keibler bemused by her antics.

The mother-of-three was seen lifting her arms and bumping and grinding while in her seat, as Kravitz appeared embarrassed and looked away.

While Demi's new beau American art dealer Vito Schnabel, 26, was at the event, the pair didn't pose up together, but were rumoured to have indulged in a passionate PDA inside.

Classy. Vito is friends with Paris Hilton which explains everything. Is this a cry for help? I'm not one to make fun of one's decline but she needs to get herself together. A 50-year-old mother partying like she's 20? It's one thing to date a 26 y/o, it's another to be seen out acting like a 26 y/o.