Yes, I think it's Sex. But I don't consider it the same as vaginal intercourse. It is still a form of penetration since it is penetrating an orifice in the body, but I don't consider it a loss of virginity in the vaginal sense. Anal, Oral, and Vaginal are all sex of their own forms. As for why the are called Vaginal Sex, Anal Sex and Oral Sex.
Making these sexual hierarchies (eg. penis in vagina is the most real kind of sex and other activities are kind of sex but not as much) says that a lot of queer sex is less legitimate than heterosexual sex, which is not cool...or true.
The answer is in the name. Oral SEX. It's not the same as penetrative sex, or penis in vagina sex, or penis in anus sex, but it's still sex. Someone's genitals are being stimulated somehow, so that's sex to me, however you do it.