They wear too little, they laugh too loudly and they are overly familiar with your man. Welcome to the world of women who flirt on your turf.

So, you're at a party with your boyfriend. You're standing in a group, chit-chatting with your friends, having a lovely time. All of a sudden, a woman you barely know is embracing your boyfriend in an enormous hug of familiarity and he is looking sheepishly pleased. She is wearing a tiny spangly top - more of a handkerchief really - and she is whispering conspiratorially in his ear. They throw their heads back and laugh uproariously at something she has said. When they look back at each other,you notice that her breasts are practically parked on his chest.

You give him a look and your boyfriend says 'Darling, you remember so and so' and you do, from the last time you were at a party and she rubbed herself all over him like a cat scenting her territory. You say hello and she seems to be extravagantly pleased to see you. She'll say something like 'I love what you're wearing,' and the friendliness and the flattery are supposed to reassure you that she's not trying to muscle in on your bloke.But it doesn't reassure you at all. You would like to cut her head off and boil it until her eyeballs explode.

Welcome to the world of Flirts On Your Turf. These women share common tactics. They are always wearing too little. In fact, they are always wearing something your boyfriend would not approve of if you wore it. Their breasts hang out, they smile all the time and they laugh at everything your perfectly ordinary boyfriend says as if he were Gore Vidal and Oscar Wilde rolled into one.

Flirts are touchy feely people, although oddly enough only with men. They touch the man they're talking to in innocuous enough places - little pats on the arm for example; there's not a law against that. And they invariably talk about things that they have in common with the man: mutual friends, work experiences etc., things that exclude you from the conversation. The bit of friendliness, which they toss in at the end to the girlfriend, is a professional touch and these women are nothing if not professional. They know that without it, even the man would cotton on to what's really going on. Or at least he would find it harder to pretend not to.

Because that's what's so infuriating about these predatory women. They weave a web of intrigue that is by definition against you, and the one person who ought to be on your team - your boyfriend - is acting dumb. He is now in cahoots with the Flirt On Your Turf. And you are, effectively,the outsider.

Flirts On Your Turf have other techniques which they employ behind your back. They send your boyfriend emails, ostensibly work related, and then suggest that they meet up for a drink to discuss 'the project'. If your boyfriend has children from a previous relationship, they might try and get at him that way. They might suggest a glamorous day out for his kids and if she has her own children, they have another whole level of bonding not open to you. Using children in this way is, of course, despicable, but your boyfriend will tell you that you're just being mean if you point it out to him. Why? (a) Because the Flirt On Your Turf has established her maternal credentials. (b)Because any implicit criticism about how he looks after his kids will make him defensive. And (c) because he has been relieved of the burden of thinking of something to do with them.

The party scenario I described at the beginning happened to my friend Elizabeth recently. By the end of the evening, a bit the worse for drink,she ended up in the back of a minicab at 2am trying to discuss what had happened with her boyfriend. He said she was imagining things. He said thatthe woman in question was a longstanding friend of his. She said that that was odd, because they'd been going out for a year and she'd never even heard of this woman before. The argument dragged on for days and Elizabeth sounded like a drone - exactly the result a Flirt On Your Turf is after.Why would you boyfriend want to be with draggy, moany you when he could bewith vivacious breast woman?

Now we have located the flirt's common tactics we can get to the bottom of this issue in part two. Read on?