At the time, there was a civil war in Guatemala. The U.S. was backing the government, and that government did some pretty awful things (during the war, 200,000 people were killed, and over 40,000 disappeared). However, America's ambassador to Guatemala, Marilyn McAfee, was pretty free about criticizing said government. The government that was backed by the CIA.
So, at one point a Guatemalan colonel ordered the Guatemalan Intelligence Service (GIS) to bug McAfee's office in the hope of digging up some dirt on her that he could then use to curry favor with his CIA handler. And he got his dirt: evidence that the married McAfee was having a lesbian affair. At one point they heard her say, "Oh, Murphy ... I love you. Give me some kisses. You're such a bad girl ..." Note that that McAfee's secretary was a lady named Carol Murphy. Busted!
When you scissor out of wedlock, you scissor the American flag in half.
The colonel relayed the evidence of this scandalous situation to his friends at the CIA. The agency began deeply investigating McAfee's life, recording a detailed log of both McAfee and Murphy's movements. The CIA station chief then confronted McAfee about it, and she was confused, to say the least.