Need Relationship advice

Jessika

My bf got upset at me the other day for something small and then for the past three days he hasn’t spoken to me much, texts me back in one or two words, doesn’t sit with me at lunch, doesn’t kiss me goodbye or anything. Idk what to do or say to him to see what’s wrong because I asked before and he says he’s fine. He seems fine with his friends but not with me :/