The cute couple were spotted holding hands in London last night (9 October) after Ariana jetted to the UK to promote her music and new Nickleodeon show Sam & Cat.
Dressed in a thick monochrome jacket and with her hair styled half up and half down, 20-year-old Ariana looked a little coy as they left trendy restaurant Sushi Samba.
Nathan, meanwhile, looked smart but casual in a grey v-neck jersey and smiled wryly at photographers while clutching Ariana's hand.
On Monday, Nathan took Ariana to his hometown in Gloucester so she could meet his parents and they were spotted together at a local train station.
Speaking later at the Pride Of Britain Awards 2013, the boy band star admitted: "I took her back to Gloucester to meet all my family.
"I was so scared, you don't even realise. But my family think she's amazing and they're like, 'Nathan, how?' and I'm like, 'I don't know'. I feel very lucky, put it that way."
Ariana first got close to Nathan after recording duet 'Almost Is Never Enough' with him earlier this year. They confirmed their romance last month after they were spotted holding hands at Disneyland in California.
"She's amazing, I'm so happy... she's a really special girl. I hope we'll be together for a very long time," Nathan added. Aww!