In the second photo, it looks like he could have a boner pointing to his left running parallel to his belt, but it's hard to say with certainty. If you share good humor together, you could make a joke about it. If you'd rather not say anything, then ask your friend to go to the gym with you or to do some kind of athletic activity where you would wear gym shorts or sweat pants. Often you'll be able to see details that you won't see in regular street clothes.