Wide-ranging classes in sex education, long denied to Fairfax County students, will be offered to their parents beginning next week.

The Woodson High School PTA is sponsoring a series of evening lectures on sex, including talks on adolescent pregancy, abortion, birth control, rape, incest, masturbation and alternative life styles (such as homosexuality). All such subjects are forbidden in high school sex education classes.

The first class, to be held Wednesday evening, will cover adolescent sexuality and communication skills. Moderator Sylia Bame will ask parents whether they would like to bring their children to any of the remaining sessions. If parents decide to include teen-agers at any of the remaining lectures, Woodson would pioneer the way toward more liberalized sex education -- under the watchful eyes of concerned parents.

A sizable -- and very vocal -- group of parents in Fairfax County objects to any liberalization of the present program, a four-hour sex education course open only to students with their parents' permission.

During testimony before the school board last year, however, a number of parents asked for an evening program that would allow parents and children to attend sex education classes together.

PTA officials said the lectures are open to all Fairfax County parents.

Lectures will be held in Woodson's choir room and will begin at 7:30 p.m. Lecture dates and topics are:

Jan. 28 -- Adolescent sexuality and communication skills;

Feb. 18 -- Sex education in the church and home, influence of school sex education programs;

March 11 -- Venereal disease and its implications;

April 8 -- Adolescent pregnancy, abortion and birth control;

May 13 -- Rape, incest, masturbation and alternative life styles.