Why do guys lose complete feel of sex after ejaculation of jacking off? -
Essentially, it all has to do with brain biochemistry. Hormones like testosterone are what get us into trouble in the first place, making us excited and -sexed up- when we see women (or in some guys, men).
A whole cocktail (sorry about the pun) of chemistry starts floating around in your brain and this results in physical excitement as well.
After sex, a whole new slew of chemicals are released to tell you to cool it. Evolutionarily, if we didn-t have this response, after sex we would just want it again... and again... and again... The chemicals released allow our bodies to take a breather. They affect one both physically (harder to get it up) and mentally (the whole idea of sex just doesn-t seem that exciting anymore).
If our brain didn-t have these on/off signals, we would probably never be able to get anything done... :)
it is all about evolution.
because the end result is ejaculation - the sperm, so the guy can fertilize a woman. since the guy already ejaculated his sperm which should be enough to make a woman pregnant, so there is no need for a guy to get sexually excited again. it would be just a waste of time and energy. so he can save the energy for better things.