Taking control: Sexual harmony is all in the mind

Sex is cold but rows are hot? The final part of our series looks at why relationships go wrong

It was the pants episode that broke her. Three months of living with her boyfriend and none of us had heard a moan from Simone. She would come down the pub for a girls' night out and we'd quiz her on how it was going. Fantastic, she'd say. Lots of wild sex. Perfect. Until one night she told us she'd found a pair of well-worn pants draped over a casserole dish on the stove.

"I used to find his untidiness quite charming," she said. "But in those days I had the luxury of escaping from his place to the relative calm of mine - where the floor was still visible and the kitchen didn't resemble a war zone. But now his untidy bedroom is my untidy bedroom, and it's my bathroom that's decorated with wet towels and scummy bits of shaving foam."

Simone and Ian have been together for more than two years, and for the latter six months have spent nearly all their time together. There seemed little point in their not living together - it would avoid the endless tramping across town with knickers and toothbrush, and put a stop to misunderstandings over the phone. Simone talked about it with us before she moved, but didn't feel that she was making any big commitment, or that things would change. She hadn't realised that her space would be his space, and her casserole dish would be the last resting-place for his pants.

Simone is far from alone in failing to realise that moving in together makes quite a change to the routine and rhythm of a relationship. Judy Cunnington, of London Marriage Guidance, believes that many people are simply not aware of what they're getting into when they move in with each other. "Even when you haven't said marriage vows, there is still a level of commitment attached to living together. You've agreed to share something and bring a new level of intimacy to your relationship - even if you're not aware of having done that."

For Simone, it is the everydayness of sharing with Ian that frustrates her.

"The trouble comes," she believes, "from the fact that many women are used to sharing with women - who are good about sharing the washing-up and cleaning. Men living together often don't care about their surroundings, and their idea of emotional bonding is leching together at Baywatch."

"It's a compromise," says Simone, the next time we see her. "I was naive, and thought we'd just slip into being together all the time. But Ian's not suddenly going to develop a liking of washing-up, and I'm not going to be happy living in a flat that looks as if it's been stirred up with a large spoon.

"We're starting to realise our differences and come together on them. He's agreed that the kitchen should become a pants-free area and I've finally agreed that he can put his Heavy Metal CDs in the lounge." She pauses. "Mind you, I never said that he could actually play them ..."