Most people, when they grow up, realize they're attracted to people of the other sex. But some people realize that they're attracted to people of the same sex.
Lesbians are women who love, or are attracted to, other women.
Gay men love, or are attracted to, other men. Bisexual people can be attracted to people of either sex. Five Ways to Address Gay Issues in the Classroom Use the words. From time to time, use the words yourself and check out the children's understanding. Convey in your approach that these aren't bad words.