Cameron Diaz and Benji Madden are reportedly "inseparable".

The blonde actress and Good Charlotte rocker are rumoured to be dating after they were spotted out at the gym together earlier this month. While they have only been snapped hanging out once, it is thought the pair have been dating for around a month now and are smitten.

"Benji and Cameron have become inseparable. They both have a raucous sense of humour, and have a laugh together," a source told British magazine Closer. "Cameron will glug beer and isn't a princess. Benji is crazy about her."

It is thought Benji's brother Joel and his wife Nicole Richie are to thank for the set-up, as Nicole is close friends with Cameron and they often go hiking together. It was a low-key meal which reportedly brought the couple together last month.

"In April, Cameron moaned to Nicole and their pal Gwyneth Paltrow that she never met any men she liked," the source added. "Nicole told Cameron that Benji had fancied her for ages so she set them up. Their first date was a quiet dinner and they hit it off immediately."

Cameron has previously been linked to the likes of rapper Puff Daddy and has had relationships with A-list stars such as Justin Timberlake and Jared Leto. Benji too has romanced well-known females including Paris Hilton and Sophie Monk.

It is thought the new couple are getting serious and are even set to go on a vacation together,
"Cameron and Benji and definitely boyfriend and girlfriend. Cameron is planning a trip to Hawaii for them next month," the source revealed. "Nicole jokes that she's been bitten by the Madden bug. Cameron had no idea the perfect guy was under her nose all along."