Sexual Relationships 
Sexual Health 
To me as a man, it is also very romantic to fall into this other plane of life with my loved one next to me. Yet, sometimes I am misunderstood. It is a well known fact that men get sleepy after sex. And this can sometimes annoy their partners. At the very moment a woman is in need of affection, a delicate show of love, a reassurance of togetherness, trust, and safety, the expected provider of all these femininely human needs turns his back and falls asleep.
The woman who was just blissfully pleased, her eyes still closed, trying to remember and relive the moment, her body still in a crazy fluid traffic, reaches her arm to her partner expressing the need for cuddling, is suddenly awakened by a wild snore coming from this human being sleeping with her in the same bed.
It does not matter if they have been together for ten years or thirty years. At that moment of bewilderment the woman may still think that this man is a total stranger. A stranger to woman kind. Someone who does not know anything about feelings. A brute. A wild man.
Oxytocin also stimulates the brain so that the body feels a bond and a feeling to be close to his or her partner. Gamma amino butyric acid and endorphins have a calming effect, a relaxed feeling which tickles the brain to signal for a serene sleep.
And here comes the most important verdict, the prolactin. Prolactin is produced in the pituitary gland and it is a stimulant for milk production. Both women and men have certain levels of prolactin in their bodies. However, after orgasm, the body releases a higher dose of prolactin, possibly to relieve sexual arousal and take our mind off sex. The prolactin levels are naturally higher during sleep.
In fact, animals injected with prolactin become quickly tired and immediately go to sleep in a corner of their cages lined up on the wall of a university laboratory. Prolactin seems to be the answer, scientists say. And I believe in science.
Yet, there is one other hypothesis that I have personally developed and would like to share with you. In the beginning there was hunting. Men must go out to hunt to feed the women and the kids waiting in the cave. It was a daily routine for him. He must reproduce, get some sleep, and go out hunting again. If he did not feel the need for some rest, he would not sleep, could not rest and it would be a bad hunting day. In those times, a bad hunting day means starvation.
There also those practical reasons that we cannot deny. Most of the time sex is staged horizontally, lying on a bed, at night, or under dim lights which are all good reasons to fall asleep.
So the desire to fall asleep after sex is in our hormones and our brains - not in our hearts.
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