It only took 3 years
Today SO asked me to buy a lock, because he is going to start locking up food in the pantry, because he is sick and tired if YSD making messes in the kitchen by making food all day when she is supposed to be in class and wasting it.
I did this 3 years ago when both SDs were getting into everything. I had food prepared for them in the fridge they could just heat up. Cereal, Raman and stuff to make sandwiches. No reason for them to get into everything and waste it. SO thought I was barbaric and would unlock the pantry when I wasn't home and let them do what they wanted.
Now that YSD is here full time, SO suddenly has less patience for her nonsense. He also admits her behavior is immature and problematic.
I also think he is scared because OSD continues to spiral out of control. She isn't with us, he hasn't spoken to her and I don't believe he wants to. I have also stood my ground that I don't want her here. I can't handle both OSD and YSD being here but am willing to accept the lesser of the problems.
He hasn't spoken to the girls older sister in years. He got a call from her complaining about how out of control OSD is. She told SO she had to ban her from her house. This seems to be an ongoing pattern with OSD where she keeps getting banned from relatives homes.
Although SO has not admitted his role in in creating SKs behavior problems. I find it interesting that he suddenly feels the need to step up his game.
It may be the new counselor they have begun seeing. I know her and wouldn't be surprised if she has called him out. He will never admit this to me. But I am happy to see the change.