Hi and welcome to PT! What a story. I can see the bind you are in. However, I am prolly going to say what you don't want to hear. Keep Friendly puss! He obviously prefers your house, and the company of Dudley, to his own. While I feel sorry for the young boy, offer to let him come over whenever he is around. As young kids are, he may grow out of his infactuation with the kitty.

I think FP has made the decision you can't...and remember, if he IS going to a secret cat gym...he might be able to beat you up if you keep locking him out of 'his' home...

Best of luck with your ultimate decision. Hope you stick around here and pester us with pics of both of your kitties...he he he.