Depends on the definition of virgin---any penetrating activity involving genitals vs vaginal intercourse. Apparently a wide spread belief among teens that you are a virgin until vaginal intercourse, hence the increase of pharyngeal chlamydia, gonorrhea, HPV, herpes and what ever other STIs. I recall a penile group A strep infection as a result of oral activities. Just because the act can't result in pregnancy does not make you immune from STI, in fact non-vaginal intercourse has a generally higher risk profile
The 8th grade health teacher is reinforcing abstinence among his 13-14 year old class: you aren't old enough to be a parent, do you want to live with hepatitis, HPV, HIV or herpes for the rest of your life? And yes oral genital, oral anal, and anal-genital contact can transmit all of these diseases. My son was traumatized by egg cell plus sperm cell = baby this should be more fun this year!