Most couples have sex less frequently as obsessive dopaminergic love evolves into companionate H&N love. This makes sense, since oxytocin and vasopressin suppress the release of testosterone. In a similar way, testosterone suppresses the release of oxytocin and vasopressin, which helps explain why men with naturally high quantities of testosterone in their blood are less likely to marry. Similarly, single men have more testosterone than married men. And if a man’s marriage becomes unstable, his vasopressin falls, and his testosterone goes up.
