This is simply not acceptable. Not to me, and if you think about your children in the same house, I think, probably not to you.
That said, I will admit that when my son was using, there were many times that I knew of "unacceptable" actions in my home, and chose not to say anything sometimes because I because I did not know what to say, and other times because I knew that I was not ready or willing to do what needed to be done. Silence was preferable (to me, at that time) to bluster and yelling, with no real consequences for him. Yes, there were times I destroyed/and or disposed of his stash/paraphernalia, and waited for him to realize what I'd done. Big deal. He never said anything to me, other than to ask what happened to it, and then he went and got more. Clearly, my disposal of the materials did not affect his addiction or behavior.
The big deal in your situation, as I see it, is that he is using and storing his stuff in your home under the noses of your children. That, for me, would be a "turning point." A line I could not let him cross again. Not because he's an addict. But because of the kids and the danger to them. It's like leaving poison (actual and virtual) within reach, and I could not stand that he made that choice. His choices for himself are one thing. But we are obliged to protect our children, and he has endangered them. Complicity in that would not be acceptable to me, as a Mom.
There are hard choices to make, but I think that making them will not be something you will ultimately regret. I wish you strength and courage, and the peace from knowing that you are taking a necessary step.