I would say accept your knees - as long as they bend and flex and help you run and jump and squat and kick things, then they are truly wonderful things.
I have fat knees, fat legs, all over but I DO love them, they are the BEST at kicking things and squats and running and doing all the things I ask them to, and they hardly ever complain!
Your problem also reminds me of a ballet dancer I knew - she was THIN THIN and probably about 90lbs soaking wet. She would moan, "I'm so fat... Look I can pinch an inch!" To pinch this inch she had to bend at the waist... Then pinch the skin that folded there when she bent!
Yeah, you're HUGE darlin! This to me, when I weighed over 200lbs.
I don't know if you weight train, but training with weights will dramatically change your body composition and may help you have a lower percentage of fat, which may get rid of your "fat knees".
Also, something which I keep reminding myself of - stuff like fat does tend to squidge around when we bend - try doing a sit-up without producing a belly roll!!! Imagine if stuff didn't move around, we'd be stiff as boards!