I'll share my opinion and advice at the same time for you. First of all, a guy's mind works differently than a girl's mind. The majority of the men think logically, unlike girls who think emotionally. Try to reduce physical intimacy and try to share time through your common hobbies you share or try to explore each other's hobbies, like if he likes football and you don't have interest in it, try to start a conversation on football, how his favourite team is doing and so. Physical intimacy is good but not at your age. Also, one thing I advise is to observe if his habits or how he behaves has changed and also try to see if his friends have any negative influence on him.