I think it would be pussy-cat eyes; "kitten-cat" seems strange to me. We do say "kitty-cat", usually when calling a cat: "Heeere, kitty-cat!" (like the Russian "ки�?а-ки�?а"). "Pussy-cat" is both gentler and sexier. To call a cat, we also say just "Heeere, kitty-kitty-kitty." Which makes me wonder if "kitty" in this usage, as well as the Russian "kisa", might be onomatopoetic, from the clicking sound cats make when they are on the hunt – a sort of "ki ki ki" sound – to alert the other cats in the family to come and join them (at least my cats make this sound).