The first thing one notices in this photo is the very distinct curve of the male's erection.  It has not only a u-curve but also curves to the side (the man's left). In the photo research the 22% of erections that had a u-curve including 2.5% that had the combination u and left curve illustrated here.  The remainder of erections are: 15% with an n-curve (including some with an n-curve plus a side curve) and 63% that were straight when viewed in profile. Subtract from those "profile straight" erections the 9% that curved to the side, and that leaves only 54% that were completely straight when viewed either from the top or the side. So, while the majority are straight, that leaves a rather large minority (46%) that have a curve in one direction or another.  Most of these males with curved erections are comfortable and happy with their erection shape.  There is no rule written somewhere that says erections have to be straight.  This 27 year old man is 5 ft. 6 in. tall and weighs 140 lbs.