I feel your pain. Sassy is aging and is less and less active everyday. I can't stand seeing her not wanting to play anymore. Whats next? She won't want to go on walks? I hope that day never comes. She really loves walks at the moment and I can't picture her not liking them. But if that day comes I'll be pretty upset. I hope you can have many many more happy years with Simba. He's lived a full, happy life with you and your family and he still is.