Sharing sexually explicit photos, videos or messages — or sexting — seems to be increasingly common among teens today. About 27 percent of teens say they’ve received such an electronic message, or sext, according to a study in the journal JAMA Pediatrics that included more than 110,000 teens. Nearly 15 percent admitted to having sent a sext. About 12 percent also said they had forwarded a sext without permission. Boys were as likely to sext as were girls, and older teens were more likely than younger teens to sext. Phones were used for sexting more often than computers. The study, which assessed data from 39 studies published from 2009 to 2016, also showed that sexting has increased in recent years. The result of all of this? The study’s authors warned that sexts, especially ones seen by people other than the intended recipient, could lead to harassment and cyberbullying — perhaps even sexual assault and suicide. The message for parents? Talk to your kids — early and often — about the risks and consequences of sexting. Also make sure they understand that, once sent, a sext can live forever on the Web. Along with the study, JAMA Pediatrics also published a guide: “What Parents Need to Know About Sexting.”