A saying usually said after one exposes extreme femininity. (usually a male) Adapted by a very male name "Justin," Justina is the name referred to any man exhibiting any form of panzy-ness or woman-like qualities. In other words, a man acting as if he possesses a vagina.
Boy: Ugh I don't understand why she isn't calling me? What am I doing wrong!?
Boy's friend: ...Says Justina
Boy: The world hates me today, I'm going to order like 5 Big Macs.
Boy's Friend: ...says Justina, would you like a tampon with those?