Good or interesting reads on sex and bonding brain chemistry.
There is no discussion on the wisdom of how to be happy or to use this information to have a healthy, stable relationship in connection with this human brain chemistry.

BBC Science | Human Body & Mind | Science of Love

• Dopamine - Also activated by cocaine and nicotine.
• Norepinephrine - Otherwise known as adrenalin. Starts us sweating and gets the heart racing.
• Serotonin - One of love's most important chemicals and one that may actually send us temporarily insane.
• Oxytocin - This is released by the hypothalamus gland during child birth and also helps the breast express milk. It helps cement the strong bond between mother and child. It is also released by both sexes during orgasm and it is thought that it promotes bonding when adults are intimate. The theory goes that the more sex a couple has, the deeper their bond becomes
• Vasopressin - Another important chemical in the long-term commitment stage. It is an important controller of the kidney and its role in long-term relationships was discovered when scientists looked at the prairie vole

Study: Oxytocin ('the Love Hormone') Makes Men in Relationships Want to Stay Away From Other Women - Lindsay Abrams - The Atlantic

Only about a study on Oxytocin