Some British parents say they want a sex education study guide used in high school to be removed because it is "shockingly explicit."

The 60-page guide, produced by Coordination Group Publications, is used by thousands of secondary schools. It's intended to teach personal, social and health education to 14- to 16-year-olds -- but some parents object to the level of detail and the "chatty" style, the Sunday Telegraph reported.

The guide suggests students engage in "sexual touching, talking dirty face-to-face or on the phone and sending sexy e-mail and text messages" to "warm-up" for sexual intercourse, the Telegraph said.

Simon Cook, a spokesman for Coordination Group Publications, said the chatty style was done purposefully.

"It discusses serious issues and gives sensible advice in an accessible style that young people can understand," said Cook. "Not everyone may appreciate the chatty style, but it helps to demystify the subject."