Sweet Japanese Onomatopoeia

ぬくぬく　nuku nuku　- a cosy winter feeling of being curled

すりすり　suri suri - the sound/feeling of a cat skimming over your cloth

くんく　kunku - the expression of a dog sniffing on you/something

にこにこ　niko niko - doing a smiling face

しくしく　shiku shiku - a sobbing feeling

いちゃいちゃしてる　icha icha shiteru - getting physically close with someone (but as a nasty expression, like fumbling around)