Just as guys help their girlfriends and wives check for breast cancer [1], you can help your man check for testicular cancer. You might not know this, but it's the most common cancer in American males between the ages of 15 and 40 [2]; a pretty scary stat! If it's found early though, it's highly treatable, so it's important to encourage your man to check for lumps or changes in his testicles [3], and you can help too. Here's how:

• Find a time when your man isn't wearing underwear, but not before or after sex for two reasons: One, it's a total mood killer to think about cancer when you're trying to be intimate, and two, if your man is aroused, his testicles will be too swollen and sensitive to get a good feel.
• First do a visual check. Usually one testicle hangs a little lower, which is totally normal. What you're looking for is any swelling in the skin.
• Then take both hands and gently cup his testicles — check both carefully. Keep in mind that testicles are usually smooth, oval-shaped, somewhat firm, and one testicle may be be larger than the other. As you gently roll his business between your thumb and forefingers, feel for lumps, swelling, or hardness. You may feel a cord leading from the top of each testicle, but that's normal too. When you do this check-up once a month, be on the lookout for any changes.
• If you think you've found something, or your man has noticed pain or aching in his groin area, he should get in to see his doctor ASAP.

Source [4]