There's a long history here, but I'll leave that out for the sake of brevity. Name changed because DM knows I use MN.
DS is turning 3. DM and DF want to get him a gift for his birthday. Their original idea was one of those electric cars they sit in and drive, which I said no to. She then asked what to get him for his birthday, so I gave her a list (little drum kits, stuff for the garden etc). She ignored said list and proceeded to visit a toy store and send me pics of various gifts. I said no to some and yes to others, and suggested various different alternatives. They (she and DF) made a purchase, stated it was not from the list and said that they'd decided to keep it secret from me until the birthday.
Anyway, DM couldn't help herself and blurted out during discussion about something else that they'd bought DS a trike (that I'd explicitly said no to in the chat when she sent me a photo). I've told her we have no need for it (he already has a bike and a scooter), no space for it (we're desperately trying to cut down on toy clutter, they know this) and that they can keep it at their house. DM said she'll bring it to our house on DS's birthday anyway and take it back again. I've said no and that if it is brought here there will be a fall-out.
DM thinks I should just be grateful for what I'm given for DS and says that she only thought of what would make him happy. I think it's less about what will make DS happy and more about what DM wants to buy. I'd honestly be happy with no gifts- she buys him something every time we see her (weekly) and we have enough stuff to keep a soft play running, but given our history, there is a chance I'm overreacting.
AIBU?