In fact, just two weeks ago, Lindsay and Gavin were warned that Riley will die soon.
And so the heartbroken parents brought their wedding forward by four months so that their little superstar could be there.
The couple, from Burnholme, North Yorkshire, then set about rearranging bookings for the wedding venue, as well as cars and photographers and the making of her wedding dress.
Mum, Lindsay, 25, who already has two daughters, Ebony, eight, and Kelsy, five, said: "It was really special having Riley at our wedding on Sunday.
"It was such a rush trying to get everything done for the wedding at such short notice, but luckily friends and family helped and we managed to pull it off.
"It was a lovely day, especially because Riley could be there with us.
"He was on good form and really enjoyed dressing up like a grown-up in his suit, we had a lot of fun."
Riley was first diagnosed with the atypical teratoid rhabdoid tumour after he started being sick at Christmas last year.
Just before Easter, Riley was so weak he could stopped walking and a CT scan showed the tumour on Riley's brain.
He had an operation and underwent a course of chemotherapy before doctors decided there was no more they could do.
They stopped treatment at the start of July when an MRI scan showed a shadow on the back of his neck.
While doctors couldn't confirm whether or not it was a tumour, the family was informed that he had a cluster of cells which could turn into one. His brain and spinal fluid were also tested and they discovered these were now riddled with cancer.
Riley's dad, Gavin, 24, who is a private with the Royal Signals, now wants to make sure the family create happy memories with the time they do have left with Riley.
He said: "We are just devastated - it's like our whole world has been crushed. It feels like we are in a bubble.
"Riley's nothing like he was before he was diagnosed and he never will be again, but since he finished his chemotherapy he has been much happier - smiling and dancing, he loves to dance.
"But his condition will only get worse. Every day we see him getting a little bit weaker and it's heartbreaking."
The couple are fundraising to take Riley on a dream holiday to Disneyland in Paris - with the help of Yorkshire Children's charity Make a Dream - before he becomes too ill.
They have already raised £5,000 in donations from family and friends.
Gavin said: "We're trying to cram as much into the weeks he has left so that he's happy, and so we have some good memories - because memories are all we'll have after he's gone."