soo i need advice

my moms been married to my stepdad for almost three years now. things moved super fast between them they got married after knowing each other for like 8 months and we all moved in w him two months after me and my brothers met him. he’s a pretty cool guy tho and i can tell he rly loves my mom so i never said anything bc i js want her to be happy since her and my dad split. for the past year tho i’ve been feeling rly uncomfortable around him. he’s always telling me i’m beautiful he smacks my butt all the time he’s grabbed my thigh a few times and has asked me some super inappropriate questions. he’s asked me if i want him to buy me a sex toy (i’m 16). we have a pool at our house and i rly don’t even feel comfortable in my bathing suit if he’s there. i used to sleep naked until he told me he would come in my room to check on me and said he pulled the blanket back up for me cuz i kinda kicked it off. idk maybe i’m js overthinking and js need to calm down but i’ve been harassed so many times before and i never know how to deal w it. i know most ppl are going to say to talk to my mom but me and my mom have the worst relationship and i’m so scared of her and she never believes anything i say so i don’t think telling her would help it would js make things worse. he does do a lot for me and my brothers tho and my moms happy and i dont want to ruin that. should i js keep quiet and js wait till i move out in a few years?