peter-in-law
A relational distinction. If you sleep with a girl, then your buddy sleeps with her. You are his peter-in-law. The relationship is one way. You would not be his peter-in-law unless you sleep with that girl again *after* him.
Sean Penn (Madonna's ex-husband) is the peter-in-law of Guy Ritchie (and let's face facts, a bunch of other people too!)
peter-in-law by Jeff Lebowski June 9, 2004
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