The immortal words of
Mr Hankey the Christmas Poo.
Though in this instance Mr Hankey was referring to The Virgin Mary we can all learn something from his words. What they mean of course is that you can still technically be a virgin while giving as much head as you want.
Throughout the ages many people just assume that oral sex is a part of sex that thus if you ask someone "How many people have you had sex with?" then it is assumed that you are asking if they have been blowing people too. A recent example of this is in the movie Clerks.