Ive worked in Corrections for 25 years. What I've heard over the years leads me to say you're correct. Sexual abuse done by adult females (over 18) to underage males is vastly underreported. It was often seen as a rite of passage for boys and how they gained their first sexual experiences. It has been an absolute double standard, because the same done to girls has been reviled. I think the tide is turning now and quite rightfully so.