Porter will occasionally swat around his favorite toy (mouse-mouse), although his favorite fun happens when Mark would play with him. He would play-bite and scratch and roll around with Mark. Now, he has Charlie to play with and it is much better for everyone. Mark doesn't get bloodied in the battle and Porter has someone who will bite and scratch back so the two cats learn about boundaries with each other and what is truly playing and what is not tolerated from each other.
When we had only Porter I was constantly asking myself is he was really happy in our home. He seemed bored and had little interest in us besides the time we fed, brushed, or petted him. With two cats now under one roof I truly feel they are both very happy now. Porter has a friend to play with and nap with and argue with. Charlie has a chew-toy with Porter's tail and a warm body to sleep next to. All is good in the world :)