Marlene is to men what Boomhauer is to women: uses them for a brief fling, only to get a new lover when she gets tired of her current fling. It is because of this that Boomhauer finally realizes what it is liked to be used.
Marlene is first seen in the episode as a jogger whom Bill had fancied. Marlene meets Boomhauer after falling into potholes that Bill and Dale had dug up and tripped on, only for Boomhauer to sweep Marlene off of her feet before Bill could get to her. As time passes, Boomhauer starts to fall in love with Marlene and becomes distraught when she stops returning his calls and contact with him. Marlene even rejected Boomhauer's offer of marriage and revealed herself as a woman who uses other men one night, leaving Boomhauer heartbroken and in a similar state to Bill, whom was not a stranger to the sting of heartbreak, and is snapped out of it by Bill before that depression and state became permanent.
Ever since being turned down and used by Marlene for sex and nothing more, Boomhauer has noticeably curbed his womanizing ways, having felt the pain of being used and rejected. Boomhauer even apologized to the Ice Cream Lady, a woman whose heart he had broken earlier on in the episode, something he never did before this incident.