Abi,
This sounds like something that puzzled me quite abit but I eventually I cracked it! See my post and pictures http://www.breastnexus.com/showthread.php?tid=9317&pid=62965#pid62965

Basically its because a male rib cage tapers down, so as the boobs grow out the nipples move down, so where we measure across them moves down the rib cage taper and the underbust measurement actually reduces irrespective of anything else.

Pansy Mae

(10-09-2013, 09:50 PM)AbiDrew85 Wrote: OK... Something else very strange just happened. I could've sworn that my underbust couldn't possibly get any tinier, yet I just measured again because my 32 band bras weren't digging in any longer... They're actually getting really quite comfy and at first I suspected I needed new bras... And I probably do cuz the underwires are starting to dig in... Which tells me it's time to go up a cup... But the loss of elasticity I thought was happening? Apparently not.

It's VERY VERY strange but I seem to have lost some more underbust. It's now literally like 31.5" or 80 cm.

My shoulders are still just as big though so I actually need to go up a cup size and down a band size on my end goal size. 32DD! Yikes!