It shows a lack of respect on my part. Instead of asking for their input, or asking their permission, I discount their feelings and make some absolute statement about my expectations. That may fly when they are age five, or even nine, but it no longer has an appropriate application at age sixteen.
So I need to adapt. I want them to be adults and I give them adult responsibilities, but I still want to treat them as "children," and they are willing to accept that role when it's convenient for them. But they can't have it both ways, and neither can I. They cannot flip-flop between being dependent children and independent adults indefinitely. It's time to step up. It's time to leave the shores of childhood behind. They need to grow up and so do I.
I let my young adult children be young adults. I treat them with courtesy and respect, and stop making demands and telling them what to do as if they were still small children.