I'll post a pic soon.
God damn men
No, I don't think you understand. Let me explain.
I don't really care about your breasts. The Internet is a cavalcade of every sort of imaginable pornography I could ever want to acquire. I could, at this moment, indulge in well over a thousand different fetishes, very likely at no cost. I will gain no sexual pleasure from your breasts.
What is at stake here is a matter of the societal order. In the physical world, your being female grants you an advantage over men. It makes us want to do things for you. It makes us want to be nice to you. In general, it places you above us. It is readily identifiable in the physical world whether you are or not female, however. This distinction is not so easy to make on the Internet, and therefore we, through long years of work, have created an acceptable standard for proving that you are, indeed, what you say you are. This has grown into the admittedly vulgar "TITS OR GTFO". This should be the standard of any conversation on the Internet that takes place with a claimed, but unverified, female.
And yes, it is necessary that it be vulgar. In the event you don't give in, we need not treat you any differently, and we are on equal footing. In the event that you do, we have been placed on equal footing again, except that now we can be entirely honest with one another and carry on. You will be female, of course, and we will act as is accustomed. But we will also have forced to you to post a demeaning picture, and in so doing, harmony is maintained.
I hope that you have learned something about the customs of the Internet today. I'm available for any and all questions, and there will be a quiz next Tuesday.
EDIT: And for further clarification, because this is also pretty important to the customs of the Internet, pedophilia only applies to an attraction to those who are prepubescent. Therefore, a desire to view the breasts of a seventeen year old would not qualify as such. The word you're looking for in this case - if this had anything to do with sexual interest at all - is ephebophilia, and for most of human history was generally considered to be pretty A-okay.