This is easy. Just put it on him! Seriously, he’s probably hoping you will all the time but doesn’t want to ask. You watch how hard he gets when you ask for it or reach for it and you’ll have your answer.
You need to take the lead initiating his cock being caged, it’s YOUR job. it just is, trust me.
But this time, be meaner. Leave him in it longer, tease him harder, make him go down on you more.
Trust me, you’ll see how much he wants it. Stop thinking about it and just do it. He’ll love you for it.