answer?

so when i was around 5 i used to sleep over my cousins house. they would lock me in a room and i would see my older cousins touch each other they were 11 and 13. they would tell me to join them and sometimes i would cause they would tell me its okay but i got a lil older and i felt my mom would get mad at me so i avoided them. is that normal? im not sure if thats something normal or if its molestation or sexual abuse. when i was a kid and i would tell my tia or my mom no one would believe me once they brought my younger sister into it with them and i watched but no one would belive me or her. she was younger so i dont think she understood and now that im older i know what happened to us was wrong but i dont know what it is... i told them again recently now that im 17 and they told me everyone has secrets they need to keep to themselves. can i hear your thoughts?