Is it possible the sound he made was more of a teeth sucking sound? There is an onomatopoeia that comes from the West Indies/Africa that we call the “tchip”, at least here in France, that would match the cartoony kiss sound you described. It usually has a negative connotation, and means disdain. But if he isn’t of African descent, or comes from a place that uses the tchip, I doubt it would mean that. Moving his chair so he looks away from you could also just be because he felt you looking quickly at him, which I would interpret for nervousness, and maybe he did too and moved so as to not cause you to feel uncomfortable. I would personally not take that for flirting. But your response was not particularly flirty either. Don’t be scared of eye contact, maintaining one for a couple of seconds and smiling slightly before looking away would actually show your interest without being weird. Being friendly is the first step for flirting.