興奮するThere's nothing more powerful than a man telling you (or showing you) that your current body drives him crazy. caresses on the back, slowly descending massages, direct but gentle stimulation of the clitoris
興奮しないNot asking what you like, not listening when you say "softer", "slower" or "not here". At this age many of us know exactly what turns us on (or not), and if he ignores that or gets offended, the chemistry is over.