Leonardo DiCaprio is said to have got "super steamy" with Rihanna as the pair partied on Saturday night at the Playboy Mansion.
The actor and the singer were spotted at Nikki Erwin's 30th birthday party getting "hot and heavy".
TMZ claims a couple of eyewitnesses saw the pair shared a sneaky kiss but a friend of Leonardo's has spoken to the gossip website, claiming that's not the case.
Various other stars including Tom Hardy, Paris Hilton, Pamela Anderson, Tobey Maguire and Naomi Campbell were all also present.
Leo's said to have been invited to the event by Nikki's producer boyfriend Chuck Pacheco, and whilst it's not known whether or not he left with the stunner, they both ended up at an after-party with 50 Cent.
Jokingly photobombing a picture of Naomi and 50 Cent at the party, the hip-hop icon uploaded the image to his Instagram account.
Tagged in Paris Hilton Leonardo DiCaprio Rihanna