if they were his toys that he brought into your room, I see no problem with this arrangement. I also see no problem with bro saying, “these aren’t mine” and sticking them in the trash or give-away pile!
I am the Meanest Mommy in the Whole Wide World. I am forced to make rules & observations that I never knew would be necessary before I became a parent.
Rules by the Meanest Mommy in the Whole Wide World 
if they were his toys that he brought into your room, I see no problem with this arrangement. I also see no problem with bro saying, “these aren’t mine” and sticking them in the trash or give-away pile!