This is the emotional moment a father, who had spent six years in jail, dressed up as Spider-Man to surprise his son on his birthday.

A video of the heartwarming reunion shows Moe, who has Down Syndrome, spending his 14th birthday at a trampoline park near Orem, Utah in the United States when dad, Marcum, walks in dressed as "Spidey".

Marcum bounces over to his son but he does not recognise him in the superhero outfit.

Only when dad takes off the mask, does Moe realise that his father is standing right front of him, outside the prison walls for the first time in six years.

Father and son enjoy an emotional embrace.

"Spider-Man was also his favourite superhero," mum Lorien said.

"Moe's reaction to seeing daddy outside of prison walls for the first time in six years was absolutely priceless," she added.

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Moe is a teenager who has Down syndrome. This was his 14th birthday and we set up an amazing surprise for him! His Daddy, Marcum, had been incarcerated for 6 years! Spider-Man was also his favorite super hero. So we came up with the idea to have Marcum dress up as Spider-Man and surprise Moe for the first time in 6 years! Moe's reaction to seeing daddy outside of prison walls for the first time in 6 years was absolutely priceless!