I've just had another row with my Mum over DS1
He's her favourite grandchild, she openly admits it and doesn't try to hide it
She's always saying things to him like "why don't you come and live with me and you can have X and X and do whatever you want" and things of that nature, especially since my youngest was born, she makes little digs about how Mummy's busy with the baby so you come to Granny's etc etc - all jokingly of course 
If I ask him to do anything for me in her presence she makes digs about how he's 'my little slave' and it'll get worse when this baby is born and 'the poor kid will be made to do everything' - this is generally in response to something like me asking him to pass me something not asking him to do the washing and make dinner
So to today's argument - DS1 has asthma and we go on holiday this weekend, so I want to get full inhalers from the doctor to take with us, I said in passing on Monday that I was nipping to the doctors to put a prescription in, she told me she'd done it on Friday because she had the repeat thing you get when you pick a prescription up from last time she picked one up for me (she wasn't asked to pick it up) oh ok thanks I say
So this morning she's asked me if I'd picked it up, I say no I'm going to do it today she reminds me the doctors surgery is shut half a day on Wednesday so I say "oh yeah I'll probably pick it up tomorrow then" - really not a big deal
And she went off on one, telling me I need to get my priorities straight and that DS's health just isn't important to me anymore, the prescription request wouldn't even have gone in if she hadn't have done it because I just don't care, thank god someone cares about him ... And on and on and on
I'd like to point out at this stage that DS has in-halers that he's using atm, he doesn't need this prescription I just want to take a full one away with us for peace of mind
So I've told her she's being bizarre and stopped engaging with her
Now she's calling me rude and saying she would never speak to her Mother the way I speak to her

I'm baffled
Not looking for any answers I just want to say eeeeuuuuurrrrgggghhhhhh
He's MY son, FUCK OFF!!! 