It's believed they've been dating since 2016 and are now living together.

And New Zealand pop star Lorde, 22, appeared in happy spirits with her boyfriend Justin Warren, 33, in her home city of Auckland on Sunday.

The Royals star and her partner-of-three-years, who works as a promotions director for Universal Music, were seen buying homewares.

Is Lorde secretly engaged? The Royals star, 22, flashed a ring on her wedding finger while shopping for homewares with her boyfriend Justin Warren, 33, in Auckland on Sunday

Lorde, whose real name is Ella Marija Lani Yelich-O'Connor, was seen carrying an assortment of Persian rugs.

The couple looked casual and comfortable as they loaded several luxury items into their car.

Despite regular public displays of affection, Lorde and Justin have never officially announced they are together.

Buying a Persian rug for their new home? Lorde and Justin, who works as a promotions director for Universal Music, were seen buying homewares

Lorde paired a silk maxi skirt and white T-shirt with comfortable black Birkenstocks for the outing.

She styled her brunette locks up in a bun, accessorised with aviator sunglasses and opted for minimal makeup.

The Green Light hitmaker was also seen wearing a ring on her left hand, sparking rumours of a secret engagement.

It's unclear whether the ring holds any special significance for the couple, as Lorde has worn rings on that finger in the past.

White on the mark! Keeping things casual, Lorde paired a silk maxi skirt and white T-shirt with comfortable black Birkenstocks

Lorde and Justin were first photographed frolicking on the beach together in 2016, but at the time Justin dismissed rumours they were dating.

He told the New Zealand Herald: 'Ella and I have worked together for years and we're good friends. Any rumours of us being "a pair" are ridiculous.'

But in the years since, they have toured the world together and Justin has even been spotted near the star's AUD$2.8million villa.

Something to tell us? The Green Light hitmaker was also seen wearing a ring on her left hand, sparking rumours of a secret engagement

Lorde, who is known for her friendship with Taylor Swift, split with her former boyfriend James Lowe at the end of 2015.

She told Stellar magazine in June 2017 that the break-up took her to some 'crazy places' and she resorted to 'self-medicating'.

She added: 'There was an element of escapism and exploration and wanting to be myself in strange situations. After a break-up, you go to these crazy place.'

Notoriously private: Despite regular public displays of affection, Lorde and Justin have never officially announced they are together

You sure about that? Lorde and Justin were first photographed frolicking on the beach together in 2016, but at the time Justin dismissed rumours they were dating

Lorde found international fame at just 16 years old when her single Lorde became a worldwide No. 1 hit.

She returned with her sophomore album Melodrama last year, which topped the charts around the globe.

The album produced another popular single, Green Light, which reached No. 1 in her home country of New Zealand.