You've seen it in the locker room. A shredded oak tree of a bodybuilder two lockers down pulls off his shirt, and, out of the corner of your eye, you see that he's got breasts. What's happening there is called gynecomastia—male breasts. And it's most common to bodybuilders, elderly men, and teenage boys.
Dr Blau Talks About New Gynecomastia Book: Masculinity Defined! Are you embarassed by drooping pecs? Embarassed to take off your shirt in public? You're gonna wanna see this!