Not can, does
A guy needs dopamine to orgasm. He has to have energy and mental direction. He CANNOT relax. As orgasm builds, dopamine and oxytocyn build to a peak release, dopamine plummets, and prolactin rises. 1/2 the oxytocin receptors in the dick DIE (really, are absorbed), and he is unable to get a new erection for a certain period. This period is determined by the amount of prolactin. This is known as the refractory period. As long as prolactin is PEAK high, he can't get it up.
Note: The only other prolactin source I am aware of is the high people get from THC.
Prolactin is balanced against dopamine. When one goes up, the other go down.
A guy RARELY experiences prolactin (except pot smokers), usually only post orgasm. Woman get it all the time. Tweak their nipples, boom, prolactin hit. Prolactin is used to bind us to the woman that gave us the orgasm. As long as we have prolactin running around, we are nice happy IN LOVE people, socialised, easily managed, ie: pussy whipped. If a guy continues to have sex and orgasm until exhuasted, his prolactin level will be higher than the zero norm, but not much, for 2-4 days. This is the beginning of falling in love. Keep having this type of sex for 2 weeks and the woman owns him.
So how does the prolactin do it? It turns testosterone into estriol, which in turn drops the sex drives and make the guy more "family" material. It does this via the enzyme aromatase. Expose a guy to enough prolactin and he'll grow tits.
More sex equals less desire for sex.
This is NOT fair. But who said life was fair?
So how do we avoid this and continue to have sex? A LOT of it. You need to block the prolactin from turning the testosterone to estriol. This is done by taking a dropperful of passion flower extract a day. This extract is an aromatase inhibitor and will block that action. It'll also drop the refractory period and allow you to have more sex with less wait in between.
Ok? Drive not to fuck yourself to death now that you know how.