1, sexual function and the length of the penis is not related. Some “short and smart”, some seem to be very strong, but make “in the look but not in use”. 2, the penis will have a little bend when erect, and the degree also varies from person to person, this is definitely not any abnormal ability or strange disease, as long as it does not cause discomfort or hinder your sex life is normal. 3, sperm production time of about 90-116 days, and can survive in the vagina or cervix 72 hours. 4, most of the penis is caused by the spongy body, covered with a layer of epidermis, when sexually excited, the spongy body will be filled with blood, so that the penis becomes hard, longer and thicker for sexual intercourse, which is called “erection”. 5, the erection of the penis for too long and did not subside, not only will you not enjoy the pleasure of sexual desire, but also make you feel painful. Injections of drugs to treat sexual impotence or leukemia can cause such a situation. 6, never to prolong the erection or to prevent ejaculation, and in the penis on the rubber band or band, which will most likely make the blood clot, and lead to tissue necrosis of the penis. 7, when the female vagina is not lubricated enough and you forcefully enter, and the action is too intense, not only will the woman feel pain, you may also have a circumcision situation. Although the foreskin will heal on its own, but too serious will require stitches. 8, when the testicles are inflamed, the penis out of white or yellow discharge, pain when urinating or anal irritation when there is discharge, should immediately stop sexual activity, because the above symptoms can show that you may suffer from sexually transmitted diseases, should immediately go to the doctor. 9, the average man in about twenty years old when sexual activity reaches its peak state, the average day can erect 7 times. 10, men also have his G-spot, try stroking the perineum located behind the testicles near the anus, when you gently touch this “sensitive area”. He will feel very comfortable. 11, wearing tight jeans and underwear will make the testicles too hot and destroy the production of spermatozoa. 12, more than 90 percent of sexual impotence patients are due to psychological factors, only a small percentage is due to physical factors, including reproductive organ disease, hormonal imbalance, diabetes. Spinal injury. Drug abuse. Alcoholism, surgery and getting older and so on.