Shnarky can mean anything from a kiss all the way to sex and all the kinky things you could imagine inbetween.
Girl 1: Did you guys fuck?
Girl 2: No, but we shnarkied. (;
Girl 1: ..What does shnarky mean..?
Girl 2: *smiles*
Cool, Awsome, Shibby
That's Shnarky, Shnarky!,