A Nashville family is taking seriously the effort to encourage sexual abstinence among teens. Julian and Valerie Head are planning in 2010 to open their home for a father-son purity ball, "Night of Knights," at which sons will pledge celibacy until marriage and fathers will pledge to support that effort.

"I think that men have historically been more of the instigators and so the message should absolutely be more focused on them as well," Julian Head said. The Heads' 9- and 6-year-old sons will attend the ball.

The Heads recently held a similar purity event for girls; it was attended by 52 people, including the Head's 10-year-old daughter.

Events such as the purity balls come as health officials are coping with high levels of STDs among teenagers. Half of the 19 million cases of chlamydia diagnosed last year were among people ages 15-24, according to CDC.

Mark Huffman, vice president of education and training for Planned Parenthood of Middle and East Tennessee, praised the balls for getting parents and kids involved in early conversations about sexual issues. He added, however, "If you are only focusing on that one aspect [abstinence] then it just probably won't be as effective [as] conversations that include messages of responsibility. Ironically, the programs that show the best track record are programs that show themselves not to be just abstinence programs."