It sounds like he's using the good old pressure techniques. Don't fall for that crap. "Hey! Everybody is smoking this stuff. So, you should too." "All the girls do this so should you."
You'll find everybody using these kinds of pressure techniques throughout your life. Like Lonely Girl said, go with you gut and don't make yourself do it just to please him.
He might even say, "if you don't do this and this then I'm going to leave." Another pressure technique. Just say okay if you want to leave then leave I can't stop you. But, I'm not going to do this or that just because you want me to do it.
It's about confidence. I'm sure you want to please him and do the normal thing so you don't feel weird or odd. But, you have to protect your own well being because nobody else will.
You'll find guys that like to use pressure to get what they want don't stick around long and that's a good thing. It's better to get an understanding guy that cares about your feelings and what feels good to you.