AIBU for not wanting to pay rent?

So you pay rent, they expect you to subsidise their lifestyle, expect you to do childcare for free and are now pimping out your services to his family free of charge and expect you to pay the vet.

I would just move out now. I suspect it will be cheaper for you if you factored in all the unpaid work you are doing as a cost factor.

Stop being a doormat. They want their cake and to eat it.

I do think in the circumstances you’ve now outlined, that your sister is being a bit mean. I expect that your mum is just trying to keep the peace and be fair to you both. Maybe your sister is struggling financially more than you realise and they’ve started to rely on your money to make ends meet. If that’s the case, maybe do what you can to help, what goes around comes around and your sister will no doubt always remember your kindness.

Exactly this! I’m confused. You’re earning more than them together and they can afford a mortgage, child etc but you can’t! Why not? Are you being tight fisted and expecting to live in other peoples homes instead of being an adult and getting your own place?

Asķ bils family to cover your rent in return for dog sitting.

It sounds to me like your sister felt she was doing you a favour offering you their spare room while you got yourself on your feet.
Then she found out you are actually better off than she is, well and truly able to stand (financially) on your own 2 feet.
I do think your sister and BiL are being cheeky now, trying to get as much money and favours out of you as possible. But perhaps they feel like you deceived them, made them believe you were worse off than them?
Agree finding your own place ASAP is best option now.

Move your possessions out of their house, stop the babysitting, working from or visiting their home - and paying them.
Sort out a flat or house share, go no contact (but do tell them if you move out of parents house, don't leave dogs alone with no-one to feed them)

Edited as cross posted.

I think they’re using you. £100 per week for family is too much.

😆😆😆

What stands out to me is the vet bills.
If you kept my little dog, you’d have to pay over $125US every 6 weeks due to her medical needs.
Very unreasonable to ask anyone to pay that while I’m away — I’d never do it because that’s just taking advantage of someone’s kindness.
Instead, I’d make arrangements with the highway robbers who call themselves my vets.

The host family has offloaded her to their parents for a few months, while still using her for free babysitting AND demanding money for room and board at theirs, which she isn't using because she's at the parents' house.

This is still divesting OP of any responsibility. Why didn’t she say no to BIL’s parents?

I think they’re using you. £100 per week for family is too much. Plus all the other things you do on top. House sitting and dog care is something that dog owners pay for. Not get free and expect sitter to cover costs. No way. Get out of your sisters house asap.

Everyone makes fair points here- because of your agreement they took it they’d have that money for the full year but I’d add that it’s because of what you earn that this is even a thing. They saw you earn more than them combined and are just thinking ‘she’s fine she can afford it’.

Yep. Not sure if PPs are missing this or have just decided to put the boot in to OP?

The host family has offloaded her to their parents for a few months, while still using her for free babysitting AND demanding money for room and board at theirs, which she isn't using because she's at the parents' house.

It's a pity you need to move out before you'd finished saving up, @freebirdblue, but it's not your fault your sister, BIL and his parents have decided to use you as servant & cash cow rolled into one 🙁 Best to knock it on the head while you're all still speaking.

But what if they were expecting to store their belongings and to move back in at the end of this period?

You can't leave a dog for 2 months and only check in on it.

If it was me I wouldn't expect any thing from someone who isn't there

You really should’ve said no to the house sitting. Your BIL has almost set you up. Gets you out the house by recommending you to his parents to house sit, saves his parents money and gets to continue receiving £100 PW from you while they entertain their friend who will be in your room for a bit.

Is there any way you can back out now?

I wonder if they all feel you have tonnes of disposables income due to being child free and knowing your salary.

If so, you might struggle to get reimbursed for the vets too which will become another issue.

They all don’t seem to have much respect for you and you need to have better boundaries and learn to use the word no.

Any dog sitting or arrangement to do a favour shouldn't effect you. You should be paid for that work if they also expect to be paid rent. Either it's a free house sitting per care gig as a favour and bil who's idea it was understands you would do it on those conditions or they pay you as you would ABT other maid service to walk clean up and care for the dogs.

The same for the holiday in January. You said no point moving and paying twice. Ha! You don't pay to sit somebodies dogs. You could have your own house and go there rent free and do it as a favour. Price up what a live in dog sitter charges. You will be shocked. Not to mention all the childcare and pick ups etc. just buy your own place and if they require your services, don't get mugged off. Because right now you're paying them to be their aupair lol

It sounds like they have come to rely on the money you are contributing to the household in fairness, which is why she is asking you to keep paying while you are housesitting, and why they are discouraging you from leaving yet.

That isn't your problem as such, but if they are also feeding you, you really have been living there for next to nothing, and while it is obviously helping them financially, it is also doing you a massive favour in terms of saving up, so if I was earning more than their combined salaries I'd just keep paying it personally then arrange to move out after January next year.

Oh FFS. How many more threads are you going to pollute with this obtuse, sneery, patronising attitude?

If it’s all just a case of family helping each other out, why did OP even agree to the deal her sister offered in the first place? Surely she should have said, “But you’re my sister - why don’t I get to stay for free?” OP agreed to (very favourable) commercial terms - she had other options if she didn’t like them.

OP said the friend is coming to stay “on and off”. I wouldn’t expect someone to be paying rent in those circumstances.

It would, of course be perfectly acceptable for OP to say “Hang on - if you want me to pay for the room while I’m not staying in it, I don’t want anyone else staying in it either”. But she won’t say that - just as she hasn’t said she doesn’t really want to house sit for her BIL’s parents, or wants to move out even though they’re encouraging her to stay, or doesn’t want to work from home in order to provide childcare. She seems to have been struck dumb.

So much of this could be resolved by OP just speaking up. Why won’t she do it?

Glad my family don’t see helping each other out as a commercial arrangement. But I’m sure you all love each other in your own way.