Electric or acoustic guitar?
Being a musician myself my teen years were filled with playing guitar and singing with friends. If he is good enough that people will enjoy his playing he will make a lot of friends with it, I predict.
As a teen myself, I took a lot of comfort in having mine because I was good enough that I could create a lot of fun & get positive attention. In fact, I just got back into playing again and our "band night" with friends for sing alongs is one of my most favorite things to do.
If it is an electric that he plays at full volume, he is just a beginner and only knows one song, then it probably isn't such a great idea, though.