Now, this is an interesting tack ... To curb teen sexual activity and unwanted pregnancies, prosecute their parents for negligence. The effect in lawyers' fees alone should send chastity belt stocks through the roof on Wall Street ... Trial Begins in Teen Sex Lawsuit LINCOLN, Neb. (AP) -- A teen-age girl at the center of a lawsuit over her pregnancy said today that she had sex at her boyfriend's house because his mother condoned the activity. ``She said that she was 16 when she had ( her son) and that he should have a child when he was 16,'' Leanne Detmer told jurors. ``I liked being at their house because we could do what we wanted. There were no rules over there.'' Dawn Bixler is being sued by Doug and Sharon Detmer, who allege she was negligent in supervising her son and should pay the costs of the abortion their daughter had. The case is believed to be the first of its kind in this country. Doug Detmer said he and his wife were unaware their daughter was having sex with the boy, Dallas Mills, after the two 16-year-olds began dating in 1996. The girl told them she was pregnant in April 1997 and had an abortion. Sharon Detmer testified the children spent most of their time at Bixler's north Lincoln home. She said her daughter often came home late from the Bixler residence and that the Detmers once had to call police to retrieve their daughter. The Detmers are asking for more than $11,000 in medical expenses and an unspecified amount of general damages. The medical expenses also include cost of the treating the girl's depression, which was aggravated by the pregnancy, lawyer Brett McArthur said. Ms. Bixler's lawyer, Susan Strong, said the lawsuit borders on frivolous because the sex was consensual. She said Ms. Bixler suspected the two teens were having sex and confronted them. ``They laughed at her,'' Ms. Strong said. Ms. Strong said Detmer drank and was abusive toward his daughter and that she got pregnant to get back at him. ``Leanne Detmer's damages were not caused by my client,'' she said. Earlier, Lancaster County District Judge Jeffre Cheuvront ruled that Mills should be dropped from the lawsuit because the sex was consensual. In his ruling, the judge said teens had sex 15 to 20 times at various locations, including her home, his home and the home of a friend. He ruled there was no legal wrongdoing by the boy but that questions about his mother's responsibility should be decided at trial. ``The issue is whether she had a duty to act,'' Cheuvront wrote. ``Certainly it is foreseeable that harm can result to a person of tender years who finds herself pregnant.'' Simon Heller, a lawyer with the Center for Reproductive Law and Policy in New York said earlier that the lawsuit was novel. Once a person engages in some activity with another person consensually, a successful lawsuit for damages is generally considered to be impossible, Heller said.