My parents have been fostering for a very long time and the person living with us now has been with us for a few years. They've been in care since they were a baby, but have been passed around from carer to carer.
I've always tried to get along with everyone and at the start things were fine and I got along with them really well, I'd take them to the park often, let them play on my gaming consoles, borrow my books, be a person for them to talk to when they were upset, sharing snacks, cheering them up, helping with homework and basically above and beyond what any other sibling would do.
Unfortunately, over the years they have become progressively worse, they lie all the time, never listen, steal things, abuse our cat, say bad words, fighting and bullying people at school - both boys and girls. They have also been known as the student having the most detentions in the entire school. It's stressful and I am growing sick of their behaviour to the point where it feels so peaceful when they are not around and I'd rather they not be around - because they are always doing something wrong.
Despite having a massive support system and lots of people to talk to, they still do terrible things, I've noticed the way they act when we talk about and anybody can easily tell they enjoy tormenting other people. We've spoken to them about things and have encouraged them massively, we tried a reward system, treating them whenever they're good and have given them lots of positive things in their life. But strangely they are always drawn to bad things no matter what it be
Before coming to live with us, they were in a terrible condition and since they've been living with us life has improved for them massively - a complete 180, but their behaviour gets worse and worse everyday - they have even been involved with the police.
I've tried everything to improve things and so have my parents, but it's getting to be too much, they purposefully do the things I dislike and my hatred grows for them day by day - I've had enough now.
Is there any advice for a situation like this? it feels like such a mess