He was recently reported to have embraced a vegan diet, at the urging of his new girlfriend 26-year-old Julia Stambler, in a bid to improve his health.

And on Wednesday, Charlie Sheen, 51, showed that he and his belle remain very much in sync as they enjoyed a spa retreat together in Santa Barbara, California.

The couple displayed their shared sense of humour when they stepped out of the esteemed Bacara Resort & Spa wearing matching moustaches, in a comical - and ultimately unsuccessful - bid to go incognito.

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Couples retreat: Charlie Sheen and his girlfriend Julia Stambler were spotted together at the Bacara Resort & Spa in Santa Barbara, California, on Wednesday

Drinking cold beverages as they hugged during their stroll in the sunshine, Charlie sported authentic facial hair, while Julia's was of the novelty variety.

Wearing matching shades, the pair looked casually cool for their excursion, with Julia wearing a white striped T-shirt with blue skinny jeans and pristine white plimsolls.

Puffing on a cigarette, former Two And A Half Men star Charlie opted for a black polo shirt, which he teamed with baggy green shorts and a pair of black hi-tops.

They're growing on each other! The lovebirds showed their shared sense of humour as they attempted to go incognito with matching moustaches

The lovebirds were seen relaxing together on a bench as they made the most of their leisurely time on the Central Californian coastline.

Last month, Charlie - who revealed in 2015 he is HIV-positive - has reportedly been following a new vegan eating plan as part of a fitness drive with new girlfriend.

Sources told TMZ that the actor has been waking up early to go swimming and do yoga, and he's been eating plenty of rice and veggie burgers, and washing those down with coconut water coffee.

The Platoon star's vegan diet isn't the first time he's been on a health kick. In June 2016, the actor admitted he was concentrating on working out and eating better.

He said at the time: 'Now it's exercise, diet. I don't go on benders, don't drink as much. It was a combination of a lot of self-loathing, a lot of shame that was behind it. I just wanted to keep myself divorced from reality. I just woke up one day and said, "I deserve better".'

Charlie previously claimed he's been off hard drugs for a year and rarely touches alcohol nowadays, but recently admitted he has been suffering with 'borderline dementia' due to the cocktails of medication he has to take to manage HIV.

He revealed: '[The drugs] kept me suppressed and alive, but I struggled with a constant migraine and at times, borderline dementia.'

But the star also insisted he is beginning to feel like his old self again.

Health kick: The actor has reportedly been waking up early to go swimming and do yoga, and he's been eating plenty of rice and veggie burgers

He said: 'I've started to feel back to myself again and back in touch with all aspects of my life. When I was first diagnosed, I knew it wasn't a death sentence but it was just a giant frickin' bummer.

'I accept the gift of being alive. I could run and hide from this whole thing and not be outspoken and honest and open about it, but I've chosen a path that's the opposite.'

In June, it was revealed Charlie was dating 26-year-old Julia, the former nanny of his eight-year-old twins Bob and Max, who he shares with ex-wife Brooke Mueller.

Charlie and Julia, a bikini model and actress, are thought to have embarked on their romantic relationship in March.