A variation of the term 'Crossing the Rubicon'. A phrase where a woman had ventured down the path of
sleeping around, having numerous hook up sex with multiple partners, cheating on spouses, having children out of wedlock, committing adultery, initiating divorces, accumulating STDs and the like, and thus had sealed herself from any chance of ever returning to her previous identity of being a chaste female with a good upbringing and life choices that would attract men
looking for a serious
relationship.
Sally is crossing the Rubicock by dumping her boyfriend of 5 years and
sleeping around with several other men while she was on campus. Now after
graduation she is trying to get back to her ex claiming she is not
having fun anymore of doing that, to no avail.