Photo Illustration by Elizabeth Brockway/The Daily Beast/Getty/HandoutWhen accused murderer Gage Ashley’s longtime lover showed up last month at a Central New York courthouse to testify in a routine pre-trial hearing, few people expected it would be a teacher from his former high school.Mary Ferro, 61, insisted under oath that the two didn’t begin a sexual relationship until Ashley, now 26, had graduated and was of age. Still, whatever was happening concerned Ferro’s daughters enough to warn the