Goldie Hawn says "good sex" is the secret to her 40-year relationship with Kurt Russell . The 'Private Benjamin' actress, 78, has never married 'Escape From New York' actor Kurt, 73, but the pair have been together since 1983 and have 28-year-old son Wyatt. Goldie has now told E! about the key to their long romance: "You have to have good sex.

" "Because sex is something that connects you and creates more belonging. "People who have healthy sexual relationships usually last a lot longer. It's not just because of the act, it's because of the warmth and the intimacy that it creates.

" But Goldie stressed intimacy was not enough on its own to keep a relationship alive in the long-term. She added: "You have to be nice to each other upon occasion." Goldie also admitted couples don't always agree, adding: "You know, you're not the same person.

You don't think the same way oftentimes." "And you have to accept that, but you have to measure, 'Are we having fun, or is this something we want to do? Do we have laughs together? Do we share certain things?' You don't have to share everything." Goldie also advised people to let go of unrealistic views of relationships, adding: "We have a lot of expectation, I think, around relationships, but you have to like the person.

That's very important." Kurt told E! about love: "Most people that have been together for a long time, I think, share one thing in common." "And that is that after that many years together, you will have experienced just about.