The possible reasons for not having a normal erection the first time you have sex include the following: 1. psycho-psychological factors, the most likely, the first time you have sex will have emotional tension, lack of knowledge and other factors. 2. endocrine factors, the existence of hypogonadism patients will not be able to erect. 3. vascular factors, the existence of diseases that reduce blood flow in the cavernous arteries of the penis, as well as diseases of penile venous fistula, can lead to a failure to have a normal erection. 4. 4. neurogenic factors, such as diabetic peripheral neuropathy, chronic alcoholism, etc. This situation may be the result of a combination of factors, the need to promptly find the cause, targeted treatment.