My ex-bus driver seems to be a p********

Hi uhm, i am a 15 year old female student and i think my ex-bus driver is a p********. A few weeks ago i sat down inside my ex-bus drivers bus since i got out early from class and my new bus driver was still attending a different school.. i crossed my legs and my uniform skirt lifted up but i didnt realize until i saw my ex-bus driver looking down at my legs, i fixed my skirt and put my leg down, i felt super uncomfortable after that and even more uncomfortable when he kept staring at my legs with a creepy smile and look. A few days ago i entered his bus again to leave my backpack in his bus since i got out early again.. he was laying on the front seat and he looked at my body for a while then asked me “hey, why are your b**** so.. big..?” and i stuttered “w-what..?” (he is a 25+ year old and i felt uncomfortable with that question coming from an adult creepy man) and he just said “oh uh i uh its that the kids in the bus ask that..” and i felt uncomfortable so i just said “oh.. uhm i-i dont know why they are like that…” and i was gonna leave the bus when as i walked out all of a sudden i feel his hand pet my right side hip. i felt grossed out and it didnt feel like a ‘oops i bumped into his hand’, no, it felt like he put his hand on my hip and petted my hip. Monday is coming up soon and i want to tell the director but i’m scared and afraid. What should i do?