But the 19-year-old heart-throb has shot down those rumours in a recent interview with a UK magazine.
‘We’re not dating, no. We’re just friends,’ the One Direction star confirmed.
When asked whether he was bisexual, Harry replied: ‘Bisexual? Me? I don’t think so. I’m pretty sure I’m not.’
The rumour mill started whirring when the twosome were spotted clothes-swapping after wild nights out. The mill swung into full action when they pulled an all nighter at the Brits, before appearing together on 28-year-old Grimshaw’s radio breakfast show.
Despite this, Styles insists the gossip comes as part of the package of being a global super star.
‘Some of them are funny. Some of them are ridiculous. Some of them are annoying. I don’t want to be one of those people that complains about the rumours,’ he said.
‘I never like it when a celebrity goes on Twitter and says, ‘This isn’t true!’ It is what it is; I tend not to do that.’
‘The only time it gets really annoying is that if you get into a relationship and you get into a place where you really like someone and then things are being written in the papers that affect them and how they see you. Then it can get annoying.’
Meanwhile, openly gay Grimshaw seems just as blasé about the rumours.
Adding wind to that pesky rumour mill, he has even brought presenter Olly Murs into the picture.
Taking part in a celebrity football match to promote the Football Association’s 150th anniversary, Grimshaw postured in some rather interesting poses with the 29-year-old singer.
Apparently there were no hard feelings after Olly’s team beat Nick’s team in a shameful 11-1 defeat.