She engages in secretive behavior
Cheating girlfriends often become very guarded and cagey. Dr. Reena Sommer, a divorce and affair consultant and author of the book "The Anatomy of An Affair," observes that when cheating mates are working on a computer, they are often quick to close or change a program window whenever you approach.
Similarly, Dr. Robert Huizenga, an infidelity coach quoted in an article on Womansdivorce.com, says that a cheating girlfriend may begin to delete emails from her email inbox, where before she let them accumulate.
A cheating girlfriend may suddenly start taking her ringing cell phone into another room before answering it, and then delete the caller ID number once she's finished the call.
