The duo sing lovingly into each others eyes, hold hands and hold each other.
Fans have gone into a frenzy commenting their love for the couple.
Later the same night, sharing a series of flirtatious Instagram posts together, fellow musician Hugh was keen to tell his friends and fans just how he feels.
The pair have been plagued with dating rumours since co-starring on House Husbands together last year.
Delta playfully told the Kiss From A Rose singer to stop being 'jealous', but obviously enjoyed seeing the men fight for her affections.
The incident followed months of rumours that Delta and Seal were more than just friends and colleagues on The Voice.
If Sheridan’s Instagram is anything to go by they could be heading that way.
He uploaded a video yesterday of the pair singing the love song ‘When I Fall In Love’ by Nat King Cole.
Hugh was even spotted tenderly touching the back of Delta’s neck as they waited to board the boat. Hugh also posted a cheeky video to Instagram story, in which he showcased Delta pouting for the camera and said: 'Best view on Earth..Opera House is good too.'An eagle-eyed fan noticed the clip and commented 'He's smitten - this post plus his instastory...' onto his kissing selfie post.Delta's posts also fueled the gossip, with numerous videos on her Instagram story showing Hugh visibly close by.Highlight of my day was singing with beautiful @deltagoodrem ..., wasn’t hiding the fact she has found love in the arms of her leading man, kissing and cuddling handsome Hugh for all the world to see during a cruise with friends on Sydney Harbour.When asked which coach he tended to agree with more on The Voice, Seal immediately turned to Delta.'I find myself agreeing a lot more with Delta, she doesn't pull any punches, but it comes from a really good place' he insisted.'I love Delta as a person, but it goes beyond that.I have an incredible amount of respect for her and I know how hard she works.'Last week, contestant Tim had Delta dancing on the table during his performance - and they even shared a friendly kiss.She told the rugby player, 'I really am a hands-on coach!' before Seal quickly stepped in when Tim pulled out a red rose for Delta.Radiating happiness, the 32-year-old “Delta didn’t stop smiling or laughing.I’ve never seen her looking so happy or at ease,” confirms one close friend.