Adorable video of grandad opening the front door to a special visitor goes viral

More than 8 million people have watched this heart-warming video.

An 87-year old grandfather has gone viral after his granddaughter created a compilation video of his sweet reaction to her coming round to his house for dinner.

The one-minute long video was posted on Twitter last Friday by doting granddaughter Jennifer Barclay, and has been viewed by over 8 million people since.

The compilation records her granddad Robert's reactions on 17 different occasions as he opens up the front door and welcomes her into his home in Fife, Scotland, with each greeting being just as cheerful as the one before.

She captioned the video: 'My wee grandad, 87 years young and he's my number one guy.'

'I love him with all my heart. And I love recording his reactions when I come to visit. I hope everyone can appreciate the video I've made as much as I do.'

The sweet compilation also shares the different pet names that Robert has for his granddaughter, such as 'hen' and 'honey bun', which has melted hearts worldwide and sent the Twittersphere into overdrive:

One user wrote: '"Hello, honeybun”. Says it all. He loves you. Over and over and over. Best thing ever.'

Another user very touchingly replied: 'The last may have been the sweetest. I watched this with my 15-year-old daughter whose grandfathers died before and soon after her birth, and we were both so touched. What a lucky girl you are. Thank you for sharing.'

Jennifer, 24, has since set up an Instagram account entitled 'the grandad diaries' to keep fans up to date with his latest adventures.

In an interview with The Daily Express, Jennifer explained her reasoning behind uploading the video to Twitter:

'Through the year I'd been posting individual clips of him opening the door to Snapchat for family and friends. They raved about them so I thought 'What if I put them all together?' I thought it might cheer someone up, because it cheers me up every time I watch it.'

And cheer people up it certainly has... 8 million people, in fact.