AITAH for wanting my 13 year old brother in law to go back to his family

LONG POST

To keep this anonymous, I have changed a couple details. But the story remains the same.

I, (19 F) and my boyfriend (20 M) moved out of home and into our own place at 19 and 18 years old. The place was a little pricey, but it fit our needs in terms of location and space - and there was a spare bedroom for a roommate so we could split the costs a bit. We offered it to our good friend in the city who was looking to move elsewhere that had more work (we live in a very small town with many job opportunities), and she accepted. With that in mind, we went ahead and signed the lease.

Flashforward 2 months later and our "friend" basically moved out overnight with no discussions prior, and left us to pay her portion. It's a whole situation but let's just say we don't talk to her anymore and neither does the rest of our friend group.

Our rent went from paying $330 a week to $500 a week each. I am very grateful to be in the position when I can afford that as my work offers more rent assistance than I need on top of my pay. My boyfriend however, is an apprentice and has to work two jobs to match my pay and cover his portion comfortably. This is no dig on him, he is also doing an engineering course on the side and I am more than happy to support him to ensure his success. It just put a lot of strain on our relationship, and I could only spend time with him every second weekend

During this time, there was a lot of drama happening within my boyfriend's close family. His dad (54 M) and younger brother (13 M) were constantly fighting, and his dad would never be home because he wanted to stay at his new girlfriend's house. My boyfriend's 2 brothers would be left alone most of the time, the eldest only being 15 years old.

After a couple conversations with my father in law (FIL), we agreed that the youngest brother can live with us as we have a spare room, under the condition that he goes to school everyday and helps out around the house. He agreed and now covers a 3rd of our rent. He then moved into his girlfriend's house and his other son lives in their spare room.

So our rent has gone back down to $330 a week each, and I get to spend more time with my partner and also help give his little brother a better life. Oh boy was I wrong.

To put it simply, his little brother has insomnia, depression, anxiety and is suicidal. They are medicated, and attend therapy, however it has affected his education so badly and he hasn't gone to school in two years. I suggested we encourage homeschooling for now as a good way to transition back into a routine, and not fall behind. If it were fully up to me, I would have sent that boy straight to school. He has a big set of friends there that he talks to online all the time, so I'm not worried about him being lonely/bullied. Unfortunately it is not up to me, and I had to compromise with the condition that he would return to high school in the next school year.

On top of this, we have inherited his cat. It is an adorable tuxedo cat, however it is very young and used to live in a house with a lot of other animals. So it's not very well trained, and misbehaves a lot. I love cats. I have a cat of my own that also loves other cats, so I didn't mind taking it in. That was until I was the one paying for its food, litter, and was the only one giving it love and attention. My boyfriend's brother locks him out of his room and barely interacts with it. In my eyes, this is now my cat.

On top of that, I am the one paying for groceries for the house. My boyfriend's brother is rather picky and imo lazy. He won't eat any of my cooking, but he also won't cook his own meals. I have gone out of my way to buy all of his favourite food, and I have bought meal kits, snacks, frozen meals and foods, the cupboard is fully stocked with noodles and chips and chocolates, and the fridge is stocked with fruit and small veg to snack on. Yet he will complain to his dad that there is no food in our house, and have him drop off food instead (which he barely eats and leaves to rot in our fridge) We even have small appliances to help (air fryers,

On top of that...he leaves dishes and rubbish everywhere. I have asked my boyfriend time and time again to have his brother help around the house, but it makes no difference.

I would be okay with all of this somewhat, if he was attending school. But he's not. In fact, he's barely done his homeschooling. He just sleeps all day, stays up all night. Leaves the house without telling us. Invites friends over without asking us. And no matter how often I follow up with my boyfriend or my FIL, no one cracks the whip.

Another detail, my FIL is living paycheck to paycheck. Half the time he can't pay rent on time. My boyfriend's brother demands things for his dad all the time. "Can you buy me this? Can you buy me that?" And then if my FIL says no, he will guilt trip saying "You always do this. You've never been there for me. You're a terrible father" and my FIL gives in.

My FIL is paying for my brother in laws 3rd trip to the city since living with us, because he has friends there. Not as a reward, but just because. On these trips, he is going to concerts, he is extending them and is barely communicating with myself and my boyfriend.

I know that none of this is the boy's fault. He is a product of his upbringing. School was never encouraged, and the environment in that house was terrible. No kid should have to grow up in that. It's the reason my boyfriend got out when he did. And he is lucky that his smarts have carried him through life. His attendance was fairly low, however he would come in every test day and get 100%. His brothers haven't gone to school in years.

So I don't really know what to do. I constantly feel uncomfortable in my own house and I am spending hundreds of my own money to try to keep this boy happy. I'm feeling used and I am struggling to find reasons not to have this boy live with his dad again.

We are getting assigned to a company apartment/townhouse through my boyfriend's work in the next few months, which will bring our rent down to a total of 50$ a week. We have until then to decide if this boy moves with us or goes back to his dads. I am really just looking for advice. And I feel like it would be an asshole move to give up on this kid

Please let me know