Gene Simmons believes the key to a happy marriage is a healthy sex life.

The KISS bass player tied the knot with his girlfriend of 28 years, Shannon Tweed, in October despite previously claiming he would never marry and Gene admitted it is the couple's wild antics In The Bedroom that have kept them together for so long.

He told "Romance is interesting, but somebody much more prolific than I am put it better; she should be a Madonna in the kitchen and a w***e in the bedroom. That's pretty accurate."

Shannon's advice is "Keep having sex in different ways. Try to think of something new."

Gene also revealed the couple's two children Nick, 22, and Sophie, 19, are not phased by their parents' prolific lovemaking and just leave the house when they hear the "noise from upstairs".

He said: "Thank god the children are grown up. As soon as they hear noise form upstairs they leave the house. That's good."

Gene - who claims to have slept with over 2,000 women - proposed to Shannon while they were on holiday in Belize in July 2011.

As he got down on one knee, he told her: "I come with so much baggage, but you're the only friend I've got, you're the only one I've ever loved, you're the only one I love, and the only one I ever will love.

"I've never said those words to anybody, and I don't ever wanna. It's funny, they used to watch movies where they say I can't live without you but for me it's true."