Yeah man, totally, if heis interested it means that sooner or later he will smoke, with or with out you..........
Now, as far as I'm concerned, you can deal with some dodgey people in the drug world. If I were you my main concern would be this.
You know him better than us I would imagine, you should be able to make some good judgement calls on whether or not he would cope well with weed. So taking all that into consideration. I would advise that you personally see to it that he has a good first time experience
Also, he's 17! I was smoking when I was 14-15 years old! Hahaha, he should be "mature" enough. But then again, how do you measure something like maturity
Just make sure he doesn't leave shit lying around hehehe!
Good luck!