Very nice, you've captured quite the moment here. If would have been nice to see the kitty turned a bit and the boy's eyes could have been brightened a bit. Also the hair seems a tad oversharpened to me. I didn't reduce score because of these things, they're just FYI.
I REALLY like this and gave it an 8 - but wanted to come back and comment. I wish the kitty was looking at us too and your bg blowout light is a bit hot on his left (right as we are looking at it) shoulder which causes it to fade in intensity on the BG to the far left of the image. But I know this because I have the same problem - I need to get a long slim softbox 10x36 or so on a boom to get more even light on my white BG. Is that a ragdoll? Reminds me of my little Scooter when he was a babe :-) By the way, love his freckles!!
One of the better clean portraits in this challenge. Clarity colours lighting all work out nicely. I am sure the owners are thrilled with this in their hands. However for me, it really is just another portrait without much else to keep me interested. Yet, after really looking at a few others I will bump this up a bit because it does have nice technical skill.