My older brother is in college, and I am in high school. We come from a Christian family. I was showering for swimming at the exercise club with my brother, and I saw that he was wearing a rubber-like circular object around the base of his penis. I asked him what the object was, and he said it was called a cock ring. He said that the ring helped his penis to be more engorged and made him feel more manly. He said that lots of guys on his college swim team wear cock rings. His penis was super erect when we were showering, and the ring with his penis sticking out all looked kind of cool. He then put on his swim trunks over the ring, and he and I went swimming with him that way like it was no big deal. He asked if I thought it would be cool to try a cock ring like his, and I said I thought it would be kind of cool, so he told me that he's going to bring another cock ring like his for me to try for when we go swimming next weekend. He told me that it's a special kind of cock ring that is loose enough to wear for a long time, but that he would take it off if it ever felt a little too tight. If it's not a sin to masturbate like our pastor says, is it not a sin for a teenage boy to wear a cock ring?
A cock ring works by restricting the blood flow from the penis through pressure. Since more blood enters than exits, the penis inflates. This is similar to the way erections normally happen, however, the veins getting the greatest restriction are the ones near the surface of the penis and not those internal. The problem is that this keeps the blood in the penis from getting oxygen. If you haven't notice, you are not able to keep an erection for more than about 30 minutes without it feeling uncomfortable. That is because your cells in your penis are running out of oxygen. Thus, your body is designed to release an erection so that the blood can get oxygen. Keeping a cock ring on for more than 30 minutes can be harmful. Doctors recommend not keeping one on for more than 20 minutes. Falling asleep with a cock ring on would be particularly dangerous. Wearing one too long can cause nerve or tissue damage.
Solid cock rings are particularly dangerous because they cause the penis to swell, but since blood can't escape it is near impossible to get the ring off the penis. Often this leads to a trip to the emergency room to get the ring cut off. Flexible, rubberized ones have enough give to be removable from an erect penis. But the problem of leaving them on too long is still there.
We should also look at the motivation. Your brother is trying to make his penis look big underneath his swimming trunks because he has the mistaken notion that a large penis means a guy is more manly. I suspect he thinks he can pick up more girls this way, but for most girls this would be a turn off rather than a turn on. In addition, it means he is trying to find a girl through physical attraction instead of character. He is putting emphasis on worldly priorities instead of godly ones. "Do not love the world nor the things in the world. If anyone loves the world, the love of the Father is not in him. For all that is in the world, the lust of the flesh and the lust of the eyes and the boastful pride of life, is not from the Father, but is from the world. The world is passing away, and also its lusts; but the one who does the will of God lives forever" (I John 2:15-17).
Thank you for your advice. I chose not to wear a cock ring, and my older brother respected my choice.