She has just finished a promotional tour of Australia.

But it seems there is one thing Demi may have forgotten to share with her fans Down Under when she paid them a visit - the reason she is wearing a gold band featuring tiny diamonds on her wedding finger.

The 22-year-old star was sporting the simple bling when she landed at LAX on Wednesday, and did not seem to make any attempt to hide it.

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Something to tell us? Demi Lovato was seen coming through LAX on Wednesday wearing a gold band with diamonds on her wedding finger

She had also been wearing the gold band when she left Australia and boarded the plane.

The star has been dating beau Wlmer Valderama on and off for five years - they got together in 2010, but later split.

Then in 2011 they were rumoured to be on again, but then broke up again to date other people.

Wedding bling? The singer has just returned from a promotional trip to Australia but did not say she had got engaged

The pair then got together again in 2014 and have been going strong ever since.

Demi has made no mention of any nuptials with her 35-year-old other half.

However she did tell New Zealand radio show ZM in July that if Wilmer asked her to tie the knot she would definitely say yes.

Long term: She has been dating beau Wilmer Valderama on and off for five years

Nuptials in the offing: He did not accompany her on the trip - she is seen here with a minder - however she told a New Zealand radio show she would say yes if he proposed

She said: 'I am very, very in love with him. I think we’ll probably wait a little bit longer, but if he asked tomorrow, I’d say yes.'

The singer has always been very open about how supportive the actor is of her.

Wilmer helped her through her struggle with addiction, bipolar disorder, eating disorders, and cutting.

Close: The singer has been very open about how supportive the actor has been - they are pictured here together

She told the radio station: 'I am very, very in love with him. I think we’ll probably wait a little bit longer, but if he asked tomorrow, I’d say yes'

In 2010 Demi did a stint in rehab to overcome her demons, and the actor was there by her side to help her get well.

She told the radio show that when they got together, the 13 year age gap raised some eyebrows:

'I was 18 and he was 30 so people were definitely judgmental and even my parents were kind of, "Why is someone his age wanting to date someone so young?"

'And after a while everyone around us started to see that what we have was real and incredible and very special, and we’ve been together ever since.

'Obviously my family loves him [now]. People kind of stop doing that because you can see when we’re together or even just from our Instagrams that we’re very sweet to one another.'

Demi left Australia after completing some promotional commitments on Wednesday.

Sad to leave? Demi Lovato looked downcast as she walked through Sydney Airport on Wednesday after a promotional tour in Australia for her new single Cool For The Summer

Wearing black sunglasses to cover her eyes, the starlet layered up in a casual chunky knit cardigan and scarf over her T-shirt and ankle cropped jeans.

The diminutive star added black heel ankle booties to her winter ensemble, with a matching black leather designer tote resting in the crook of her arm.

The brunette beauty had her long locks pulled back into a neat, low ponytail and appeared to have minimal make-up on for the 14-hour flight.

Layering up: The pop star layered up in a long chunky knit cardigan and scarf as she left the winter weather, adding black leather booties to her cropped jeans

And despite a whirlwind visit the former American X-Factor mentor seems to have had a fun, action-packed trip as she promoted her latest single Cool For The Summer.

Demi checked out some of the native wildlife and paid a visit to Australia Zoo in Brisbane.

The purple haired popstar shared a snap of her day with the wildlife, including puckering up to a baby quokka.

Stealing her heart: Demi Lovato poked fun at boyfriend Wilmer Valdarrema on Tuesday when she planted a kiss on a quokka at Australia Zoo, telling him to 'look away' in her Instagram post

Doing the rounds: The adorable animal wasn't the only one Demi met though, with the singer seen in shots with a koala and a kangaroo

Demi declared on Instagram: 'HE LITERALLY KISSED ME!!!! Look away Wilmer Valderrama, look away.'

The diminutive animal wasn't the only one Demi met, though, as she became acquainted with a koala and a kangaroo, the latter she was particularly excited about.

'GUYS,' she excitedly wrote in bold onthe social media platform, 'F****** KANGAROOS!!!! Literally SO happy!!!! I love Australia!'

Big fan: She captioned her meeting with a kangaroo with a particularly excited message, writing 'GUYS...F****** KANGAROOS'

Adorable: Demi, who was adorned in a bright and colourful dress, was similarly excited for the koala, which she described as a 'sleepy little boo boo'

Demi, dressed in a bright turquoise dress and with fuchsia lips, was similarly excited for the koala, which she described as a 'sleepy little boo boo.'

Also while in the country, the songstress performed her latest single on Sunday's The Voice Australia Live Shows.

The former Glee star dropped jaws as she flaunted a healthy dose of skin in a revealing bra top and hotpants combo.

Bringing the heat: Demi is in Australia to promote her newest single Cool For The Summer, on Sunday performing the hit on The Voice Australia

More reserved: A day later she attended a press call in Sydney, putting her best fashion foot forward in a knee length structured black number

A day later she attended a press call in Sydney, putting her best fashion foot forward in a knee length structured black number.