[Missed Miss]

I also think of it as pretty much nothing more than body modification. If your friends and family have no problem with getting piercings and tattoos for themselves, why should they have any problem with you growing tits and changing your body to the way YOU want it? Did any of them ask your permission or input on their choice to get pierced or tattooed? I'm guessing they haven't! Therefore, how is it any of THEIR business what YOU do with YOUR body? Painting toe or fingernails, colouring, cutting or re-styling hair, and wearing make-up, even wearing clothes, are all forms of body modification. No one needs permission from anyone else to get those done.
Just be strong, state your case, make your point(s) and if any of them don't like YOUR decision of what YOU want to do with YOUR body, to hell with them!!

"I'm the only one that's got to die when it's MY time to die, so let me live my life the way I want to!"
Jimi Hendrix

Maybe this will help, too! http://youtu.be/VNXWMHu9An0