Catherine Townsend: Sleeping Around

I was on a packed flight from my dad's house in the States back to London when a hugely corpulent man claiming to be a famous musician sat down next to me and launched into X-rated tales of his various girlfriends. I tried everything to deter him, from burying my head in a magazine to feigning sleep, but he rambled on - as undeterred by my overt hostility as he was by my headphones. So I felt I had no alternative but to smile politely and give monosyllabic replies. "You are so hot," he said, pressing a crumpled business card on to my tray table. "If you and this guy Paul ever have any sexual problems, I definitely want to hook up!"

If our row was South America, he would be Brazil bursting over the armrest into adjacent countries, while I was skinny Chile, clinging to the coast.

I wondered why some men are so clueless when it comes to reading body language. It's as if they're trying to assert their dominance by entering my personal space. Or maybe they are just hammered, like my platonic male friend who tried to give me an unsolicited goodnight kiss - despite the fact that I had the palm of my hand over my mouth - by sliding his tongue into the grid between my fingers.

The first time I met Paul in a very loud Soho House, I strained to hear what he was saying. But I noticed that he waited for me to step toward him and speak into his ear rather than crowding me. The fact that he didn't get into my face made me desperate to get into his, which I did half an hour later.

My friend Michael, though, claims that women often send mixed signals. " People are always saying that if a woman is twirling her hair and licking her lips, that's some kind of universal sign," he said. "Then again, she could just have a nervous tic or be out of lip balm, so I tend to err on the side of caution unless she's really tactile and puts her hand on my knee - or sticks her tongue down my throat mid-sentence."

We're constantly hunting for the perfect chat-up line, but in reality studies estimate that when you meet a stranger, their impression of you is based 55 per cent on appearance, 38 per cent on style of speaking and a mere 7 per cent on what you say. So being too aggressive can be a deal-breaker.

Even something as simple as eye contact is emotionally loaded, since neuroscientists say that meeting another person's gaze lights up brain regions associated with rewards. But if the eye contact isn't reciprocated, the staring can feel like stalking.

About five hours into the flight, after he finally slurred that the " sexual tension between us was too powerful to ignore", I decided I'd had enough. "Wow, that's probably because I'm so excited about seeing Paul," I said. "I can't wait to tear his clothes off. He is so well hung!" It worked, because after belching loudly, he passed out and started drooling.

He was still asleep when we landed, so I ran out to meet Paul. After two weeks of simmering sexual tension, I knew that our reunion would be hot. And I couldn't wait for him to invade my personal space.

c.townsend@independent.co.uk