Ariana Grande was spotted leaving Niall Horan's house at 3am.

The 21-year-old star met up with the One Direction heartthrob for a second night in a row on Tuesday (02.06.15) when she visited his house at 10pm, not emerging from the £1 million property in Hertfordshire, South England, for five hours.

Despite having also been out partying with Niall at exclusive burlesque club Cirque Le Soir on Monday night (01.06.15) following her sold-out show in the capital, a representative for the 'One More Time' hitmaker insists she is just friends with the singer, also 21, who recently split from model Melissa Whitelaw.

They told MailOnline: ''Ariana is friends with Niall. He had a big party that she attended.''

The news comes just days after Ariana's mum Joan revealed her family had a traumatic journey over to the UK last week when they were threatened by ferry staff in Calais, France, who claimed she could not bring the musician's dogs Sirius and Toulouse over to the UK.

Recounting the tale in a 2,000-word rant, she said the pooches were ''almost murdered'' following refusals to accept their paperwork.

Venting about the situation, she wrote: ''What kind of world is this? What just happened to me? How can verbal abuse, harassment and animal cruelty threats be considered acceptable behaviour by officials, ferry personal or any other human being?''