Umm, boobs are mostly bags of fat cells. They can exercise all they want but the only thing that'll happen is they will tighten the muscle behind the boobage. It might lift them up a bit, but they won't get any bigger. Ever see a bodybuilder chick with big boobs that aren't hideously oversized implants?

As an aside, how do you make 10 pounds of fat attractive? Put a nipple on it.