yes sex can cause a male to bed wet.first it stimulates the kidneys to make more urine then it also stimulates his penis and Leigh the nerves in a man's penis head control both his sex and urination reflex! if you really had good sex that night it may have both stimulated his kidneys and oversensitized the nerveves in his penis head This has happened to me Leigh before after sex or after prolonged vigorous masterbation I fall asleep right after im done but i usually have a dream and i wake up urinating in my bed like an hour or so later