The pals were laid to rest at St Mary's RC Church in Euxton, after hundreds of people turned out to their funerals.
The graves have become the new focal point of the village's grief since the pair were killed when their Vauxhall Corsa collided with a Ford Fiesta on Dawbers Lane, Euxton, on September 24.
Their details are still to be engraved on their graves but among the scores of floral tributes were the names 'Sean' and 'John'.
The Rev John Reilly, of Euxton Parish Church, conducted John's funeral service on Friday and said the huge floral tributes reflected the community's sense of loss.
He said: "It is very moving to see, very touching. It's sobering that life can be cut short so quickly.
"One minute these two lads are fine and happy, with their futures in front of them, but in a split second they're gone.
"It's difficult to pick up the pieces, not just for the family, but for the community.
"In people's hearts and minds the spirits of John and Sean live on. In both services the light of Christ shone through the darkness."
It was the first service that The Rev Reilly, who is based at Euxton Parish Church, had taken in a Roman Catholic church but he said the fact he'd been allowed to reflected the way the tragedy had united the village.
"Like a lot of people I attended both services," he said. "I think both were very dignified. I was very impressed by the reflective nature of the young people who were there. They were very respectful.
"When we interred John's coffin next to Sean's there was a moment of reverence and reflections.
"There were tributes to Sean and John from young people at both services.
"In many ways Sean and John were quite alike. They were very open and friendly. There has been a huge outpouring of grief for the two lads."
John's funeral took place on Friday, the day after St Mary's RC Church had been at bursting point for the funeral of Sean.
Sean's family had asked those attending to wear their 'going out' clothes, saying that's what he would have wanted.
But for the location and the sombre occasion it could have been a Friday or Saturday night as the mourners filed into church in jeans and smart shirts or high heels and colourful dresses.
However there was no disguising their grief as, one by one, they took to the lectern to pay their own tribute.
Sean's heartbroken girlfriend, Nicola, spoke in a faltering voice as she paraphrased the line 'Life is like a box of chocolates, you never know what you're going to get' from the film Forrest Gump when describing her boyfriend.
"Sometimes with Sean you got a coffee cream," she said, "but I never thought that the box would be empty.
"He was my best friend, my mentor, my future, and my whole life. He had faith in me and pushed me forward. Please take care of my special man."
Earlier Father Gerald McCusker opened the service while the Children's Choir from Euxton St Mary's Primary School, where Sean was a pupil, sang the psalm 'Do not be afraid'.
The whole congregation joined in the hymn 'Walk with me O my Lord' before Sean's friends and family paid their tributes.
Family friend and chaplain of Leyland St Mary's Catholic Technology College, where Sean went to secondary school, Jim O'Donnell spoke of "a tragedy that's impossible to explain" to a lad who relished "loveable rogue activities."
He said: "I'll particularly remember a trip to Whitehough, Sean was always muddy, always missing an item of clothing, but always smiling.
"The presence here today is testament to Sean - he clearly touched the hearts of many people.
"Not by being heroic or angelic, but by being a friendly, loved, loving, ordinary young man, with a smile that deserved a smile back."
Mr O'Donnell also talked of "hope through despair" and asked for "a special place reserved for Sean, 21, and John, 20." He finished: "We'll always remember you."
Sean's brother Sam, 24, had just got back from holiday when he heard the devastating news that Sean and John had been killed in a crash in Dawber's Lane, Euxton.
He accompanied sister Stephanie to read the anonymous poem 'Miss me, but let me go.'
The funeral ended with the Jamelia song 'Something about you', which included the lyrics "You make me laugh one thousand ways," and "There's something about you and you don't even know it."
- The families of Sean and John were consulted by the Guardian about the use of the front page photograph.
Tributes pouring in...
Janetta Thompson, from Euxton, said: "John was a real gentleman. He was a young man who would do anything for anyone and a joy to have known.
"He was one of God's untarnished gems and will never be forgotten. I'm disabled and in a wheelchair, and John would always be asking if there was anything he could do to help. It's such a tragedy and he will be missed a great deal."

Adrian Ward, 21, from Langdale Road, Leyland, said: "I had the privilege of being in the same class as Sean while we were studying for the final two years of our geography GCSE at Leyland St Mary's High School between 1999 and 2001.
"The banter in which he engaged with our teacher in those classes could be described as 'being worth the admission fee alone'.
"He always seemed to be bubbly and happy, and I don't think I ever saw him looking cross at any time during those years at school.
"Sadly, I never saw him again after we left high school."

A woman from Chorley, who asked not to be named, said: "I haven't been living in Chorley very long, but this tragedy has really touched me.
"I know that many people feel the same. Although I did not know the boys or the families involved you can't help but be affected by what has happened.
"I would like to let the families know that everyone is thinking of them."