Im 13. and i have a bf. but my parents dont approve. is that a sin?

ive had this boyfriend for about a year. im 13. we dont really kiss or makeout since were still like kids and I didnt want to and he said thats okay so we just hold hands and hug and give gifts and help and stuff. but we really really like each other. but my parents dont approve. i cant tell them about him. hes my boyfriend and bestfriend and i really would like to introduce him to them someday. my siblings have met him and they approved of him and said hes very decent and smart and his mom met me and likes me and is okay with us dating. my parents once almost found out about him through my texts and they were sooooo mad and talked about how they would send me to africa because i would get pregnant and because ill do bad in school. my parents usually dont listen to me and sometimes it causes me to be really like depressed so i go to him and talk about it with him and his mom and theyre always there. shes almost like my second mom. im not dumb, ive got a 95 average, and were not gonna do something stupid. im waiting until im married to have sex, and so is he. i really like him though. hes smart and softspoken and caring and sensitive and we both share the same love for music and science. but recently, i think, im disobeying my parents. is it a sin? am i in trouble with God? im really scared. i really like him. and i really wish my parents would approve. everybody else in my family does, except for them. i know its a sin to disobey, and this is the only thing ive ever done to 'disobey' them and besides this, my sister says im pretty quiet and obedient. i thank God everyday for bringing him to me. and everytime theres a problem, i go to him about it and he takes care of it. but help. ):