Well either that, or I'm no longer fitting my bras properly 
I have always been a 34B, but recently my usuals (variety of sources, from M+S to Primark) hold one boob in but the other isn't quite covered.. at high risk of nipple popping out.. it doesn't look like they ae too small, but like my boobs have parted friends!
I tried a 32C instead but find it SO tight on the back and while it it slightly less 'apart' at the front it's still not really right.
Any suggestions? (I'm neither thin nor heavy, a 5 ft 7 9 1/2 stone 10-ish) if that makes any difference