To be honest... the reason I got mine was because I love art. I had found a sticker when I was 17 and I swore that I was going to get it tatooed on me when I turned 18. I did just that.
It's not just porn girls that have a tat in that area... I swear like 90% of girls who have tats get it there. For me it was an expression of my personality yes. The tribal part if it is the fun, wild, crazy side of me... and the butterfly represents the sweet side. Notice there's more tribal tho