Have you read "Emotional Intelligence?" I had a course on it at work and have read parts of the book. Being an emotional person myself (and someone who has cried in front of bosses), I found it an excellent read and I loved the course.

If you don't feel comfortable showing your emotions in front of someone, you'll need to come up with a way to do a "self intervention." My trick is to write--"strength" or "dignity"---on a notepad and take it in to a potentially tear invoking meeting with me. If I feel like I might start, I look down at the word.

If my boss can handle the tears, I let them fly. I tend to be very honest and it's hard for me to hide my emotions. Like Mr. Silver, I've had employees, including males, cry in front of me. It does not change my opinion of them. but then, I take a more "humanistic" approach to supervising/mgt.