I am not even close to being a full timer, in fact this year I have only dressed about once every two months. I have male boobs. They developed when I came down with Chronic Fatigue. The Dr. is not sure if there is a link or that i just happened at the same time. They are embarrassing at times when I am in drab. I can fill out a 40C bra with out any other padding. As far as cleavage is concerned, I don't like to see it on over 65 women unless they are in really, really good shape(tight and firm). At 68 and about to turn 69 and not tight or firm you won't see it on me any more even though I have it. In boy mode I just can't bring my self to bare my chest to anyone, not even my wife, who love my girl side but not naked.
