In today's politically correct environment, this is truly an interesting question. Typically, men are visual creatures.
So, the question is this. If a lady, large breasted or not, sports some above normal cleavage, workplace, social, hobby...doesn't really matter where, what's the correct thing to do? (Of course we could debate what's an above normal display all day long...)
Take a long look? Take a casual glance? Sneak a peak? Try to avoid looking altogether? I've always been of the opinion that if a gal is sporting it, a slightly longer than casual glance is acceptable. Otherwise, why would a lady put that cleavage on display?
Gotta look and look long... women are absolutely beautiful and deserve to be looked at all over. I have been caught staring at stunning beautiful ladies in yoga class especially when it’s time to bend over to touch toes or for some put their head between their legs and I am barely able to bend over and get caught looking at that awesome view ... most just smile at me and keep bending over. Yoga is awesome ;-)