While a spokesperson for Nick has insisted that he and Michael are “just friends”, Grimmy shared a snap from Michael’s birthday on Instagram last week, showing the heavily tattooed snapper sat out in the countryside.
Many pictures of the pair spending time together at Glastonbury last month have also been posted.
Despite chatting away on his Radio 1 Breakfast Show each day, Nick is usually very private when it comes to relationships.
He only publicly came out in 2012, just before he took over the breakfast show from previous host Chris Moyles.
While there has been speculation about his friendship with One Direction’s Harry Styles, Grimmy was previously linked to Italian fashion stylist Nicco Torelli.
Nick Grimshaw's Best Moments At Radio 1
Britain's Prince Charles meets Radio1 presenter Nick Grimshaw during a visit to the BBC at New Broadcasting House in London(01 of11)
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Britain's Prince Charles (2nd R) meets Radio1 presenter Nick Grimshaw (2nd L) during a visit to the British Broadcasting Corporation (BBC) at New Broadcasting House in London February 11, 2014. REUTERS/Luke MacGregor (BRITAIN - Tags: POLITICS ROYALS MEDIA SOCIETY) (credit:PA)
Radio One Celebrity Football Match - London(02 of11)
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One-derers celebrate during the celebrity football match between Nick Grimshaw's team Radio One-derers (white) and Olly Murs' team Tottenham Hot-murs (red), at Wembley Stadium, north London. (credit:PA)
Brit Awards 2014 - Show - London(03 of11)
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Nick Grimshaw announces Lorde as the winner of the Best International Female award on stage during the 2014 Brit Awards at the O2 Arena, London. (credit:PA)
Big Weekend event heads to Glasgow(04 of11)
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BBC Radio 1 DJ Nick Grimshaw ( left), with a member of the Red Hot Chilli Pipers, as he broadcasts his BBC Radio 1 Breakfast Show from BBC Scotland in Glasgow. (credit:PA)
BBC Radio1 Teen Awards launch - London(05 of11)
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Conor Maynard (left) and Nick Grimshaw at the Radio1 studios in London for the launch of the BBC Radio1 Teen Awards. A (credit:PA)
Big Weekend event heads to Glasgow(06 of11)
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Paolo Nutini (left), Rita Ora and BBC Radio 1 DJ Nick Grimshaw following his BBC Radio 1 Breakfast Show, which was broadcast from BBC Scotland in Glasgow. (credit:PA)
Royal visit to BBC - London(07 of11)
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Queen Elizabeth II talks shakes hands with radio presenter Nick Grimshaw during a visit to officially open the BBC's new 1 billion home in Portland Place central London. (credit:PA)
Grimshaw in marathon bike challenge(08 of11)
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File photo dated 30/01/14 of BBC Radio 1 DJ Nick Grimshaw who is to host his breakfast show from the saddle of a bicycle as he pedals for 12 hours in a transparent box. (credit:PA)
GQ Men of the Year Awards 2013 - London(09 of11)
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Nick Grimshaw, winner of Radio Personality, poses with Alexa Cheung backstage at the GQ Men of the Year Awards in association with Hugo Boss at the Royal Opera House, London. (credit:PA)
Radio 1 Big Weekend - Londonderry(10 of11)
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Nick Grimshaw performs at Radio One's Big Weekend, at Ebrington Square in Londonderry, Northern Ireland. (credit:PA)
Nick Grimshaw New Presenter of Radio 1's Breakfast Show - Photocall(11 of11)
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LONDON, ENGLAND - JULY 11: Nick Grimshaw is announced as the new presenter of Radio 1's Breakfast Show from the end of September at BBC Broadcasting House on July 11, 2012 in London, England. (Photo by Gareth Cattermole/Getty Images) (credit:Getty Images)