That was super. Charlie showed Finn his belly. Charlie does want to play. Finn did play too. There is still testing of the waters/boundaries but it went great. The air biting is just play/ testing too. Finn needed to potty so he sent Charlie away of Charlie just left to avoid that particular event. Lol As you already know, I am big on the cage introductions and I think this went great! Security, open feeling and you can observe without having to interfere. I was really laughing at how cute Charlie was being. Finn did really well to but I think he had potty on his mind. When ya gotta go, ya gotta go. This is a good time to use a toy on a wand or string to get them to play together over the next days. Give them some time to explore this but when Finn gets antsy, play.