Because MIL is super-controlling and decided when her sons got married, that their wives had to cook for their husbands birthdays (then for their kids as they came along). She used to cook her kids favourite meal on their birthday then passed the torch when they got married. It is basically that she wants us to invite her to a home cooked meal for every birthday in our respective houses.
As a WOHM, I feel that I should not have to cook on my birthday. (SAHM MIL says she used to always cook on her birthday because no one else was going to-FIL does not cook. Now unmarried SIL cooks for her b-day).However, my husband really has no cooking skills -which is ok because I like to cook so on a day to day basis, not an issue. If I really don't feel like cooking DH "cooks" by ordering in or we go out. Works for us. He used to order in for my birthday dinners but now with these dietary restrictions for some family members, we really can't do that anymore. So, it becomes a home cooked, no salt meal for 12 and because I am the cook in our house, I have to cook it! It's crazy I know! I am not sure what to do without running myself ragged (for my own b-day) or severely pissing off the inlaws.