I just got mine pierced! (Both) :DD for for the most part, it all depends on what he plans on wearing in it after it heals. i. e, if he wears diamond studs, its to follow the crowd, If he wares fake plugs. spacers, its for him to stand out, and something he likes the look of. If its anything else, just something he likes the look of. hope this helped :)
I got both of mine pierced about 12 years ago. I didn't really have a reason for doing so, honestly. It was just something I hadn't tried yet. I guess you could say I was trying to find my own unique identity?
That sounds lame, but it's the closest reason I can come up with, lol. It's kind of the same theory as changing your hair style. Just something different. They're still pierced to this day, and people always tell me that I pull it off well, so I guess they don't look too bad, lol.