Quoting momma of an angel:" Well my MIL just went out n bought a crib cause she thinks shes gonna be staying the night soon but SOs ... [snip!] ... on alot i dont thing i should have to about my child n if we as her parents are unwelcome then she doesnt need to be going..."
I think you're being pretty cool about it, I would have SO talk with his grandmother because that's his family so it's more of his place. And as for you guys not being allowed to go, I totally agree. If you guys aren't welcome then LO doesn't need to be going.