It is pretty obvious that all men are obsessed with breasts but most men don't make it so obvious. Not Zac Efron, though. Even when he was at the premiere of Hairspray movie and knew that he was being photographed, he did not stop looking. In this picture he is looking directly at the chest of Amanda Bynes. And he does not discriminate - big or small; it doesn't matter.
In this photo, he is again admiring the bust of Nikki Blonsky; this time I don't blame him - it is too big not to notice.