Sometimes when I masturbate, I will play with my nipples because it excites me. I can do it without lustful fantasies. Is this normal? Could God have purposely given men nipples for sexual reasons, since it arouses me? By arousing myself in this way will my body produce semen faster?
There are areas on the human body that are sexually simulating. The genitals are obvious and most guys realize that the breasts on women, particularly the nipples are also sexually stimulating to a woman. What can surprise some guys is the fact that since the basic structure of the body is same between men and women, the nipples on men, while not functional for feeding children are still wired for sexual stimulation. The nipples on men are not as sensitive as they are on women, but they still respond to touch.
Whenever a guy gets sexually aroused, his body starts producing semen faster just in case he is going to have sex. The body can't distinguish intentions.