Sir Elton John’s husband was filled with anxiety as he watched the singer’s new documentary.

The ‘Rocketman’ singer, 77, has been married to David Furnish, 61, since 2014 and the pair have sons Zachary, 13 and Elijah, 11 – and the film shows a poignant scene in which Elton discusses the prospect he will probably not be alive to see milestones in their kids’ lives.

David, who co-directed ‘Elton John: Never Too Late’ with 62-year-old filmmaker RJ Cutler, told People about the emotional moment: “I don’t think it’s a conversation you want to have with your children. I don’t want to plant that seed in their mind.

“Elton’s been through a lot, but he’s also as strong as an ox. He rarely cancels shows. He’s a strong man, and he’s a healer. He’ll probably outlive me. He’s just so tough.”

David added watching the film gave him “a lot of anxiety”, and added he wants Elton to never die.

He said: “Look, I want him to be around forever. And both of us, in the 30 years we’ve been together, we’re only just at this moment that we’ve only ever dreamed of.”

David went on about his husband recently giving up touring: “Elton was always doing 90, 100 shows a year, working constantly… and then we had our sons, and then that whole reality takes place.”

The director said five-time Grammy winning Elton’s decision to stop going on the road was not the product of an “instant epiphany”, but rather the product of them wanting to treasure as much time as possible together as a family.

David insisted: “He’s never going back on the road. He’s genuinely so happy. “So for us to be at this moment right now, after so much hard work and so much anticipation, there’s a lot of heightened emotion.”

Elton says in his documentary his kids “worry about my mortality,” and that they “love their daddy, so they want me to be around forever”.