The 'Way' singer told the new issue of Cosmopolitan that the couple's first date was a low-key affair at a hotel but Nathan made it extra special by ensuring her favourite treats had been laid out there when she arrived.
Ariana said: "We were going back to his hotel to watch a movie, and he had Ladurée macarons and sunflowers waiting - I love Parisian baked goods, and sunflowers are my favourite flower. He had taken the DVD player out of the bedroom and into the living room, because he said he didn't want to take me into the bedroom on the first date."
Rumours began swirling just before Christmas that Ariana and Nathan had quietly called time on their relationship although neither party has officially commented on the speculation.
A source told Us Weekly a split could be partly down to their hectic jetsetting careers.
Ariana, meanwhile, has been as busy as ever this month, posing for a gorgeous, glossy photoshoot for Cosmopolitan America, which hits shelves on 7 January.
"I've dealt with a lot of people not knowing what to expect from me because of my age and my personality. People often mistake my kindness for weakness, and they didn't expect much from me, because at the end of the day, I'm just a nice Italian girl from Boca."
Ariana, 20, described herself as an "old soul" in the interview and insisted she's pretty normal despite her glamorous career and showbiz life.
"I'm kind of a boring, normal girl who likes Harry Potter and to sit in her pajamas and sing. A lot of my friends are partiers, but I've never really clicked with that. I like Barbra Streisand, and when was the last time you saw Babs getting, like, turnt up? That's kind of the road that I, as a lady, would like to go down."
For more from Ariana's interview, visit Cosmopolitan.