Consider some of the evidence: Ariana was seen leaving Niall's house at 3 a.m. Um. Also? There are reports that they did some shopping together at Harrods. Oh...and Niall was spotted at Ariana's hotel.
Ariana's rep was quick to pounce on this one before it got any legs though, explaining to MailOnline why Ari was seen leaving Nialler's place in the early hours: "Ariana is friends with Niall. He had a big party that she attended."
So...just friends? We thought so.