Three months after we met Greg asked me to move into his place, forcing me to break my No 1 relationship rule: never agree to anything after midnight, or in the midst of a bout of food poisoning.

A month later I was sleeping on my friend Penny's couch. She delivered the most ill-timed yet best piece of advice I've heard about cohabiting: never move into your partner's space - always find a new place together.

I had shoehorned my life into that one-bed bachelor pad in Kilburn, northwest London, and it was an overcrowded recipe for resentment. He nearly drowned in books and I paced around guilt-ridden if I forgot to wash a cup. The flat wasn't ours; it was his and didn't I know it.

Another common mistake is to read too much into an invitation to cohabit. When Penny's boyfriend Richard began pestering her to house-hunt with him, she thought a big commitment was on the cards. She wasn't ready to settle down and the cold shoulder she offered him sent him looking for warmer climes.

She needn't have worried. Research shows that men don't take cohabitation as seriously as us girls. Richard just wanted a better flat and figured that splitting the rent and the bed was a good way to get there. But all Penny heard was: “Will you have my babies?”

Dr Funke Baffour, a clinical psychologist and relationship specialist, has some advice. “The mistake many people make is that one person has a vision of the future that the other doesn't share. It's vital that you tell each other why you want to move in; the real reasons will always show through the cracks when the relationship is under pressure down the line,” he says.

Verdict Be honest about your intentions and it won't be a deal-breaker.