Refers to the situation where a party girl gets separated from her friends in Mexico. Following the murder, the abdominal organs are removed and replaced with bags of cocaÃna. The outer abdomen is sewn back together, with party girls' body then being used as a mule to transfer the narcotics across the U.S. border, posing as Javier's girlfriend. Hence, Mexican "stitch up".
Person 1: "Did you hear what happened to Ashleigh on her party holiday in Mexico?"
Person 2: "Yeah buddy I heard, what a classic Mexican Stitch Up"