Since it seems like he avoids you and you want to unlove him, cut his contacts and stop waiting or seeing or whatsoever, just dont do those. This might feel really really difficult but trust me, this is the effective way someone could unlove. You will get reminded of him every hour and when you get reminded, just shift your focus; like go for a walk, watch your favourite show or movie, exercise or even play games. But dont try to reach him by any means.
If you want to start slower, I would ask you to stop waiting for him and shift your focus just like I said above whenever you get the thought of him. You can chat when you have some free time but dont extend the time.
I think that he might have joked when he said 10% , cause no one says something this clear and open to their partner. Like , if my gf asks me if I would cheat on her, I would say no or might joke or even prank her. And idk for sure if that was a joke or prank but I think it is...