Google results seem to indicate that he's straight - There's no page, article, tweet, etc. where he claims to be gay, except for a particular post on his facebook where he calls some other dude that he's holding in a picture his boyfriend, but it also says that the picture was taken right after they'd 'hit the tanning beds.' (They obviously hadn't.) Therefore it's dubious and is probably a joke, i.e. something to garner attention.
So, since this young lady doesn't look like he knows what a tanning bed even is, on top of the fact that he doesn't state he's gay anywhere but has certainly had companions of the female variety, I'm going to take a wild guess and say that both his 'questionable orientation' and cliche getup are just for show to attract the unique and original teen girls and boys to his music and attitude/style.
... But don't you have to look as if any mature woman would date you for your sexual orientation to be relevant?