Happy Boobs
Breast in a well-fitting bra. Usually visible in a garment which is neither too tight nor to loose, presenting the breast in a way which is prominent yet not slutty. On the contrary, unhappy boobs will a appear crushed, misshapen, uneven or strangled.
(while shopping)
Girl: Do you like that shirt?
Guy: It's nice. It totally gives you happy boobs.
Girl: Do you like that shirt?
Guy: It's nice. It totally gives you happy boobs.