San Francisco.– Teenagers often suffer emotional consequences from having sex, even when it's "only" oral sex, a study published Monday suggests. Researchers at the University of California San Francisco found that up to one-half of the sexually active teenagers in their study said they'd ever felt "used," guilty or regretful after having sex. Though such feelings were less common among teens who'd only had oral sex, about one-third reported some type of negative consequence. Dr. Sonya S. Brady and Bonnie L. Halpern-Felsher report the findings in the journal Pediatrics. The study, according to the researchers, suggests that parents should be...