My best friend and i fooled around.. but he kissed me 1st and then said it shouldnt of happened the next day??

Ok my best friend(guy) kissed me and i am a female just so u kno.and well this is what happened.i told this guy my feelings at least 3 times since we have been friends and we have been friends for 2 years.he is the only one that knows everything about me and me him.and well everytime i had said my feelings he is like i only see u as a friend and that was fine with me.and well the other night we are sittin there talkin and i was like gah why i am so ugly and stuff and he puts his arm around me like he always does just playin and stuff and then he leans his head like he is going into my lap and i turn my head and he kisses me and that kiss lasted 4 a long time.it was the best kiss i had ever had and then i stopped i was like whats going on here and he said idk ive been thinkin about this 4 months and i was like r u serious and he said yea.well long story short he (fingered me) and stuff and we made out and then he avoids me for 2 days and says he was not himself and it shouldnt of happen