Man finds out he's going to be a granddad, has adorable response when he thinks no one's looking

This is probably the most heartwarming reaction to baby news ever.

A video of a man being told there's going to be a new addition to the family has resurfaced on Reddit for a second bout of glee after being originally posted last year.

Justin and Sara Hall had hidden a camera in the room before luring Sara's dad into a room decorated with baby paraphernalia.

Sara's dad, playing it cool, realises that he's going to be a grandfather. In the presence of his daughter, he retains a calm demeanour.

But when he thinks he's all alone, he jumps around, a little baboon-like, in sheer elation.

It's a touching moment...

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There are a few other moments of granddaddy loveliness floating around on the internet.

This man's reaction is also priceless. He makes quite a remarkable noise when he finds out he's going to be a grandfather...

And it takes a while for the news to sink in for this guy - but his face is priceless when the penny does finally drop.

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