That s weak minded crap to think you can hang out with someone who does drugs and not do drugs. You are just fooling yourself. Eventually, you do it no matter who you are. People do what their friends do. Having everybody at the same place and the same time tempts people.
Friends change everything.
He s gonna use it when he s around people who do it. Involve the opposite sex. All your nervousness goes away. Easy to get laid when you re high. Mix it up with girls.