Is it possible for a penis to always be bent when erect and the cause of it be that when you've had erections in the past your jeans have always forced your penis into that bent position? To be a bit clearer, can a reason why a penis is bent be because it's been forced into being bent? Since jeans never allow the penis to be completely straight when it's erect, can that be a reason why a penis becomes bent? If so, is it possible to make your penis straight again by pressing it into a straight position with your hands when an erection happens?
Your penis becomes erect because three chambers inside fill with blood to inflate the chambers. Because there is a limit to how far the chambers can stretch, the penis becomes hard while the erection takes place.
It is often compared to the inflating of a balloon. Without air a balloon is limp, but when it is inflated it becomes stiff. Now while a balloon is being inflated, it is easy to mold its shape because all that affects it shape is the outer latex skin. But if you release the air, returning it to a limp state, and then re-inflate it without any molding, it won't follow the same shape.
Your penis is not nearly as moldable. The chambers inside are more like sponges than hollow tubes. The various connecting fibers within cause it to retain its shape. This is why an erection that goes in the wrong direction, contrary to its natural shape can be painful. The overall direction of the erection can be changed as there is a internal chord that affects the angle of your erection, but there is quite a bit of play in it -- and that chord can be stretched a bit as well over time.
Many times when you have an erection, you don't get a full blown one. Your penis gets noticeably larger, but it since it is only partially inflated, it can follow the contours of what you are wearing. In fact, often times your body "trains" itself to keep only a partial erection because a full blown one in tight spaces hurts. The body tends to avoid things that make it hurt. It is not that you can't have a full-blown erection in your jeans, but most boys quickly learn to position their penis so that erections go upwards or along a leg if they are sitting.
Mild bends in an erect penis is normal. Everyone's penis is shaped slightly different and few, if any, are perfectly straight. A distinct bend where the penis bends nearly in an "L" shape or doubles back on itself in a "U" shape is an indication that there is a blockage in one of the chambers. Most of the time, body heals itself and the blockage is repaired, but sometimes the bend persists. If it remains for more than three months, you should see an urologist. He might decide that surgery is needed to remove the blockage. It is a tough decision to have it done, but it is important if you want to enjoy sex with your wife. A severally bent penis makes sex painful since a woman's vagina doesn't obtain an "L" or "U" shape.
Trying to force a bent penis straight during erections will only cause you discomfort and it will not change the true cause of the problem.