The pair starred opposite each other in hit movie 'Grease' and their shared success gave them a special bond, which they say they will always share for life.
She said: ''We did something life-changing, making that film. [At the premiere] you got the feeling from the energy that something was happening. It was a huge response. I feel grateful to be a part of that and to have worked with him. We've stayed friends ever since.''
John added to People magazine: ''When you share that kind of meteoric success - and nothing has been able to exceed it - you share a bond. I've been through her having a child, getting divorced, losing her sister. She's been through my getting married, having children. It's wonderful and full of shared memories.''
However, fans hoping for a 'Grease' reunion will be disappointed as Olivia previously admitted she thinks it is ''a bit late now'' for a reunion now.
She said: ''I think it's a bit late now. What would you do? Put us in a nursing home? I can't imagine that working now but you never know what someone could come up with. If there was a great idea then, of course, we would consider it, or at least I would. If John was up for it then I think I would be too but we couldn't do it without each other. Let's see what the future brings.''