Dolly Parton believes humour has been a "big key" to her long-lasting marriage

She told Closer magazine: "He has a good sense of humour, as do I, and I think that has been a big key to us, because we've had a lot of fun and when things get really bad, we somehow manage to find the humour in it and that kind of lifts the load.

"But I think we're also good friends. We have a lot of respect for each other and we just try to take each other as we are.

"We don't try to change each other and make a big deal out of all the little things that some people do."

The 78-year-old singer also believes the fact she and Carl have different interests has always given them a lot to talk about.

She added: "We just have a great life, and we're different enough so, when we are together, we have things to talk about, because he's interested in what I do, but that's not his world and I'm interested in what he does, but that's not my world, but together, it's our world.

"We make our world work with all the things we do, and we're just very close."

Dolly thinks her sense of humour has also contributed to her lengthy music career.

She said: "I've had to have fun in this business.

"Everyone should try to develop a good sense of humour if you don't have one, because that makes life so much easier and so much more fun."