Uh, are you a Christian? If so, I've heard some Christians say "your body is God's temple" or something, so maybe it is vandalism, or maybe its just decoration? Haha, just do what you want. And if you still live with your parents, check with them if its okay. Oh, and one more thing, DON'T GET GAUGES (or whatever they're called, those huge circle ones...), those are just nasty.
It never meant you where gay! Sailors got Their ear pierced when they sailed around the world. As for it being a sin it may be. I know tattoos are considered a sin in the Christian bible. But then again it was written a long time ago.
There are verses in the Old Testament that include laws for the Israelites to follow in order to show that they were separate from the rest of the world. Verses like Leviticus 19:28, "Do not cut your bodies for the dead or put tattoo marks on yourselves. I am the LORD." (cont in comments)