What makes your penis smaller?
If it's cold, it can shrink.
Normally after ejaculation, or upon losing an erection, the penis shrinks because blood is allowed out of the corpus cavernosa.
cold temperature and low blood
the truth in the matter is that race has no effect in penis length. it's all about genetics it depends on your parents genes. the reason is that the color of the skin is what makes the penis look bigger or smaller. For more info on this subject refer to: http://www.livescience.com/health/070601_penis_myths.html
The foreskin is very thin so no I wouldn't say it makes you smaller. The actual penis is still the same size. However, problems can arise when the circumcision is badly done. the removal of too much skin can cause pain during erection, and over time may take part in some deformation of the penis. The skin of the penis can be stretched, but it takes more than an occasional painful erection to accomplish this…