bone croatcher
Originally a term used to describe a female who readily engages in intercourse with another woman's man. Literally encroatching on claimed genitalia. The term has since lost its gender specificity and can be used to indicate anyone, male or female who tries to get with a friend's sexual partner.
That bone croatcher skeezer Shelly got caught blowing Kevin in the back of his van as soon as Vida left the club.