Might as well pack it all up. I would Kijiji all of it, or perhaps when they come over again just start loading their trunk up and say your glad to help them get their items out as you understand it probably feels awkward to them to do it now since you saw how messy they left everything.
Mad for the bed you got for their child, you picked it up and set it all up, it’s not out of the ordinary to pack it up yourself and send it back to where you got it. If it can’t be returned, then Kijiji it like everyone else would do. If you Kijiji any of the items, then any money you make off of Kijiji is yours to cover for cleanup costs as well as unrealized storage payments.
Honestly, have you asked them why they are being like this? Simply state we have never done this to you guys (unless you have, then every thing is going to come up) so why did you do this? No point asking why it’s been so long for them to do anything about it as you won’t get an answer for that beyond they feel awkward.
And get the answer out of them. Don’t let them off the hook. By doing so, you’ll keep family ties in place which is what you want, and at the same time you will put a standard in place that neither side takes advantage of each other a standard of mutual respect instead of being a piece of carpet to be walked upon again and again.
Lastly, keep us all informed! That’s the most important advice any of us can give you now
