hang out the besom

   obsolete

   to live riotously during your wife's absence

   A besom is a broom, once the preferred mode of transportation of witches, the aged menial who wielded it, and, in the 19th century, a prostitute because 'A girl described as "a besom" without a qualifying adj. would imply unchastity'. {EDD)

   Inn signs were often poles with tufts on them, which looked like besoms. One way and another, a man hanging out the besom was consorting with unchaste women, or frequenting the pub, or both. However, a woman who was said to hang out the broomstick was no more than scheming to get herself a husband, the sign telling people that she was open for business.