I'm not sure how I might compare to your "massive chest" ... Perhaps my avatar might be an indicator ... But when I need to hide my top I have a PP09 Gynecomastia Vest from Medical Inc., Picture Perfect Compression Garments. I think I ordered it from Amazon as I recall. It works OK, it's kind of uncomfortable directly against the skin, but it works well when placed over an undershirt. As far a "binding" goes, you don't have to squish completely flat you know ... A loose fitting shirt (or hoodie) helps, but if someone notices a bulge or a bump, let them wonder! That's part of the fun. If it's your boss, tell him it's a gynecomastia condition ... He or she can look that up and leave you alone. Maybe he or she will be jealous! Roberto