please help me i have a question!!!!

okay theres this guy and i went to elementary school with him and then after sixth grade he left my school and tehn now two years later he skype calls me (video calls me on a webcam) and asks me out i said yes and now tomorrow he wants to see a movie with him and i said yes well i though all was good but then i was just skyping him and his friend whos a girl and well i think she was high and i have been hearin rumors how he smokes but idk iff there true cause i havent seen him in two years idk what to do and if i do decide to tell him i dont want to datew him anymore how do i?????? please help