Demi Lovato and Jutes are already planning a special celebration for their one-year anniversary

A source who spotted the pair at the recent Clive Davis pre-Grammy party in Los Angeles - told DailyMail.com: "They held hands the whole night and were very sweet with each other - there were plenty of kisses,.

"He seemed madly in love as he touched her back and patiently waited as she talked to fans. At one point he fetched her a drink and then asked if she needed anything else.

"She called him 'honey' and 'sweetie' a lot and kept smiling at him, then went in for a few kisses. They were clearly the happiest couple in the room.

"Heidi Klum, Madison Beer, Darren Criss, they all came up to her and say hello, she seemed popular. Jutes did not seem to mind that she received so much attention."

Meanwhile, Demi previously revealed that the couple's relationship is so solid because they were friends before they became "lovers".

She told Who What Wear: "We became friends before we became lovers.

"I opened up to him because I was going through a really rough time when I made Holy F***. I had just come out of treatment, and I was newly sober and raw with my emotions. I had nothing to medicate with.

"He was there for me as a friend, helping me get through this deep depression I was in."

The Confident singer has previously dated the likes of Joe Jonas, Wilmer Valderrama and Max Ehrich, and she feels she's learned a lot from her past relationship experiences.

She shared: "I had been in past relationships where I thought, 'Oh, this is the long game!' But I hadn't taken care of myself yet.

"The universe rewards you when you do the therapeutic work on yourself, [and] I had to do the work. Because of that, the universe provided. I got myself ready for a life by myself, and then I was able to share it with somebody else."