Yes, I have a 5 year old cat. She used to suckle on my chin when I was sat down and then she started doing it to my eyes!! My mum said it might be because she liked the taste of my make-up (yuk!). Cats love the smell and taste of perfume, could this be why? Otherwise, yeah, I think it is a sign of affection, especially in a young cat. My cat was always purring like mad when she did it, although she hardly does it now so maybe your kitten will grow out of it.