I have been with my partner for 10 years. I have 2 BS and he has 2 BD - we have no children together.

The kids have always got on well together (apart from the two sisters who used to fight before they were 'split up').

We both used to have joint custody 50/50 and even managed to have all the kids same days and weekends, despite the manipulative and destructive actions of BM. Although things were never perfect, the breaks between visits from the girls made it bearable, although, on our Thursdays 'off' we used to have almighty rows!

4 years ago, BM moved away with one of her many boyfrieds to a town 2 1/2 hours drive from here. There was a big fight over the girls as she had just planned to move them away without even discussing or asking my partner.

In the end, the youngest daughter went with her, but the eldest (and always the problem one) stayed with us.

I can honestly say that the last 4 years have been HELL. My two boys are well behaved generally, quiet, polite and do what they are told without a fuss. They have their moments, but generally BS11 & BS13 are easy.

SD17, however - where do I start?

She has always been a madam - far too grown up for her years from an early start due to her mum and dad treating her like an adult, thus creating a precocious little so and so. Even my partners mum has commented in the past on how she used to be as a toddler, ie way before I met her aged 7.

From the age of 7, she has consistently played us off against her BM - Quite normal I suppose judging from posts to this site, however, the lies and tale telling have spiralled into something more. She is SO manipulaitive, there are things she does that only I know she is doing to hurt me - everyone else, including her dad miss it completely, and accuse me of making it up if I say anything. She is currently on a major pay-off between me and her dad causing an almighty argument last night. He is, of course, on her side AGAIN

Since she has lived here, she has wrecked furniture, carpets, ignored my rules regarding taking food around the house and into her bedroom. Every time she is chastised for it, you receive a mouthful back. It's like she thinks she is too important and should never be criticised.

My main issue is, however, how 2 faced she is (or should that be 3 or 4 faced?). There are different voices for addressing different people depending on what she is after. At home, she currently adopts a monotone drawl, which comes across as being really arrogant (which she is). Round her friends she acts and speaks like shes 7 - all excited and over the top, however, as soon as they're gone, she bitches about them. The voice that REALLY bugs me, however, is the one she uses on the phone, and to our friends. Its this sickly sweet, ever so meek and helpful voice - total suck up.

At home she does NOTHING. I always ask my kids to help out (they do more than she ever did at their age), and although mine grumble a bit, they do it. She will say 'I have homework so I cant help clear up tea - do you want me to fail my exams?'. Around at our friends, however, she creeps like hell and can't do enough to help. As a result, all our friends think she is lovely, and I'm convinced they have decided that I am evil step-mum who makes it all up about her.

Her dad/ my partner knows her faults, but conveniently glosses over them if it is me suffering (although, if he is on the receiving end, he expects ME to back him up!).

She is very studious - she works at that, I will give her that, but gets high and mighty about her studying expecting us all to fit in around her.

She has to be centre of attention at all times. If I am talking to her dad, she will butt in and say 'Anyway...' and then turn the conversation back to herself (usually a long monologue about her day, her achievements, how great she is..blah blah'. If there is silence in the house, she'll fill it either whistling, or speak-talking lyrics in the arrogant drawl. Any accident or misfortune (particularly by me), she will find hillarious and will false laugh on and on and on'. Then there's her fake cough which she uses to announce her impending arrival in the room, usually when we have guests. Any friends that come over, she hangs about and dominates the conversation when I just want a break and talk to my friends. But no...she is charming!

She never used to get along with her sister. Her sister is younger and georgeous looking and SD17 was always jealous. However, SD17 is skinny and does have striking features and has become a model already earnign well despite still being at school. This has made her arrogance worse. From the minute she comes in, its pure noise - singing, false laughing etc followed by self indulging monologue and a list of things she wants/ needs/ expects. At 17 I would have expected her to be out with her friends all the time, but no, she tags along with us EVERYWHERE!

She wont add me as a friend on her Facebook, as she claims she needs to keep her activity 'private', yet she has invited all our friends to join. I think this is so that she can start conversations with our friends about stuff shes posted, creating a nice cosy chat which excludes me and makes me look stupid. Her dad and our friends don't seem to see what shes up to.

Her sister lives away with her mum, and they seem to be getting along better as a result, however, interestingly, SD12 admitted that a recent mini-holiday which SD17 didn't attend the whole of due to modelling commitments, was better as a result (which it really was - I was so relaxed and had a really nice time for once!). Every single holiday we have had from the beginning has been ruined at some point by SD17 throwing a strop, being rude or just moody and falling out with her bad-tempered dad.

I hate holidays with her anyway - I am conscious of parts of my figure, and after a nasty comment by her years ago whilst I was weraring a bikini, I decided never to leave my sunbed again without a sarong, and certainly never go in the water much to the disappointment of my BS x2.

There have been other comments like this since passed between her and her mum (who of course hates me still), and she bitches about me to friends in her room and on her phone.

I can't even look at her, cant bring myself to talk to her (as it just starts her of on a loud monlogue)and I avoid being around her whenever I can.

My biggest problem is that my partner seems to have high expectations of me in this area, and expects me to be like her mum or best friend. Difficult, when I can't stand her!!! Her mum does very little for her, except when there has been a row here, and then she is super-supportive of SD17 and spoils here completely. 3 times mu partner has lost it with her and told her to go live with her mum. BM has seen pound signs and starts looking at schools, but the damn girl always ends up staying here

She is currently downstairs, playing loud music on MY Ipod speaker and helping herself and her friends to whatever they want no doubt. I think she was searching for this laptop earlier - Ha. Its mine, but hers is being repaired. Even though I said last week that I will no longer be allowing any of the kids on my laptop due to viruses etc, of course her dad insists that she should be allowed to do her college work on it. By this, that involves finding a website by typing in the assisnment title and then copying and pasting the text into an essay, claiming an A, and then bragging about how clever she is. Also, she 'borrows' my kids laptops - they always let her! She does all the dodgy music downloads etc on theirs to save her own. If they asked to borrow hers, it would be a definite NO!

Selfish, self obsessed and false. I actually hope her modelling takes off, because it means she will be around a lot less, and hopefully, will start missing more holidays meaning I can start to relax and enjoy the time with my sons and SD12 who is quite 'normal' so far despite living with her crazed mother.

I have so much pent up anger about this girl I cannot possibly express to anyone. I had a row with my partner about her last night, and the blame has been placed firmly with me for that.

I feel I am wishing away the kids time as kids to avoind having to be with her, however, this just means time with my own suffers. }:)