Most Helpful Guy
I know this hurts, but you are dating a WORKING MUSICIAN. As someone who was in the school band my whole life, and worked in live audio for bands afterwards (in other words, WAS a musician and spent tons of time around musicians), there is nearly a zero chance of the two of you having a successful relationship. Musicians have a reputation for infidelity and for not making their relationships a priority FOR VERY GOOD REASON!
Assuming he has the talent, finds the right management, and gets a break or two, he'll have to tour and travel a lot. You mostly won't be able to come along, and even if you do, his job is going to take up nearly all of his time, and there simply won't be much left over for you. Plus, you're going to have to contend with women literally throwing themselves at him, along with hundreds more who merely idolize him. No man can remain faithful with that kind of constant onslaught - there is simply too much temptation, loneliness, and it's just too easy to stray.
Plus, he's 20? Are you for real? He's no where near old enough to want to settle down, even if he was an office worker or something. But a 20-year-old working musician? You've simply got no chance. None. Nada.
I'm sure this isn't what you want to hear, but I've seen it so many times it's boring. Hell, I even got 1-2% of what the band got just by being the sound guy, and it's INTENSE. It's only a matter of time, so decide now if it's worth spending any more of your precious time on something that will never last.
Most Helpful Girl
Having sex appeal and "wooing" a crowd is the best way for a musician to network, so he isn't wrong there. It's just what they do. They're supposed to be charismatic, entertaining, WHILE putting out good music. Only accept this behavior from your boyfriend if he has actual talent. If he doesn't and you really don't think he has a chance with his silly little band don't put up with it. If I were him and I were networking I wouldn't want you there because it would hurt your feelings. However he seems kinda waaaay selfish and making this all about him... Which is something musicians also often do. Watch out.