Soon after their affair began, Sue moved into Ronnie's Birmingham flat.  But they told everyone that it was just a convenient arrangement.  "It certainly was a lot more convenient than walking Sue back to her hotel at six o'clock in the morning!" said Ronnie.

But two members of the Crossroads cast shared the secret - Roger Tonge, who played Sandy, and Sue Hanson, who plays Diane.  "Rog was my best friend, so I couldn't keep it from him how I felt about Sue," Ronnie said.  "Sue Hanson is another dear friend so before long we confided in her."

Sue Lloyd reckons the rest of the cast must have suspected their secret.  She said:  "Whenever we had to act a scene together, the vibes between us must have been felt by others."

The physical attraction between the two of them was so strong that they ended up making love on their second date.  She said:  "On our first night out together we just talked and talked - I don't know how we kept our hands off each other.  We went out for dinner again the next night - and this time there was no holding us."

Ronnie would have liked Sue to leave Richard straight away - but he tried hard not to put pressure on her.  "She became very good at the deceit," he said.  "It was hard for her, because by nature she is an honest person."

Richard never suspected anything.  When the couple split a year later he still did not know that Ronnie was the third corner of a love triangle.  Sue said:  "Richard wanted to move house and I realised this was my opportunity to end the relationship.  I told Richard I wasn't going with him but I never told him why."

Sue has had several long affairs with men, including two broken engagements and brief flings with Sean Connery and the late Peter Sellars.

"So I know about men," she says.  "But Ronnie is special - I've never felt like this before.  Being with Ronnie is the most natural thing in the world."

Ronnie agrees.  He said:  "I've had plenty of affairs with women - I lived with an American girl when I was a drama student.  But Sue is the love of my life.  We have no reason to get married.  We've made our commitment."

The couple have a small flat in Edgbaston, Birmingham, near the Crossroads studio, and two homes in London.  "Normally we share my house in London and rent out Sue's flat," said Ronnie.  "But at the moment there are builders working on the house so we're spending our time at the flat.  We shall have to sell the Birmingham flat and that's upsetting us both very much - it was our first home together."

In London the couple lead a busy social life.  "Sue has gradually introduced me to her wide circle of friends," said Ronnie.  "I used to have a much quieter life until Miss Lloyd stepped into it!  We eat out all the time - the only thing we've got in the food cupboard is a bottle of HP sauce for the take-aways."

For Sue, whose movie roles include The Stud and The Bitch, life has quietened down since she met Ronnie.  "He's tamed me," she said.  "I used to do the nightclub scene, but I can't keep up with that now.  I don't know how Joan Collins does it.  Some of Ronnie has rubbed off on me.  I'm leading a quieter sort of life - and I'm loving it."