why am i so different when im around my parents?

why am i so different around my parents but i be myself when im around friends? my parents arent abusive, they expressed multiple times that i can tell them anything no matter how small its about, they are supportive, overall they love me. but why am i still hesitant to talk to my parents about how im feeling or whatever im going through? i feel like its all my fault and i should stop being a coward and talk to them. i feel like im just too sensitive. i hate the fact that i cry so easily. why am i like this?

(sorry if my grammar is bad because english is my second language and also im crying a waterfall rn lmao)