This has to be cultural and there seems to be evidence that you went along with their ways when living with them for eight months. I am wondering if that was rent free? Do you work @Loyaltotheoil.
To me it sounds inapproproate and not something I woukd expect. When bil fell out with his papa, why was there an assumption you and you and your DH would put him up? Do you live independently in a property for which you have saved up and bought or rent through the open market. If not, arrangements do tend to come with strings attached
When MIL's texts were received, I'd have automatically written back:
The butter dish is on the table and he has a butter knife - please ask him to make sure he does not leave crumbs in the butter.
His laundry is his responsibility; if he doesn't want to deal with it, this drycleaner also does shirts/general laundry.
If he wants pancakes/cake, there is a nice cafe down the road. I am already providing three meals.
If, he has any further requests, please ask him to speak to me directly, as he is living under our roof, where our domestic practices apply. If he wants more, there are half a dozen estate agents in town who deal with rentals.
See you soon, love op.