In a survey of college students, nearly half of those who had ever sent a sexy text had lied while doing so.
Shockingly, sexters aren't always wearing or doing what they say they are, according to the new study.
"This already exists in face-to-face interactions, like with orgasms it's common," lead author Michelle Drouin told Health. "I expected people would also be 'faking it' in sexts."
Drouin worked on the study at Indiana University - Purdue University in Fort Wayne.
She and her coauthors gave 155 college students who had been in at least one committed relationship an anonymous online survey about their sexting histories.
The surveys included questions about lying to committed relationship partners via text about what they were wearing (or not wearing) and what they were doing. There were also questions about the participants' attitudes toward relationships and commitment.
Of those who had ever sent a sext, 48 percent had lied, according to the results published in Computers in Human Behavior.
At the end of the survey, an optional fill-in-the-blank section let the students explain why they lied: for themselves, for others or neither.
Two-thirds said they lied to serve their partner and one third lied to serve themselves.
About twice as many women as men had deceptively sexted, which is comparable to the research on lying during sex itself, Drouin said.
"Women are more likely to fake orgasm than men, for obvious reasons, but more likely to pretend enthusiasm as well," she said. "Women lie to serve other people more than men (do)."
We know that people can fake orgasms, or general enthusiasm, in face-to-face interactions, but texting allows people to fake entire sex, which is new, she said.
"The fact that deception can occur so easily over text, I think it is a problem," Drouin said. "Especially because this generation uses it for so much."
Based on the relationship attitude questions, people who were more anxious about relationships or who tried to avoid closeness were more likely to have lied in sexts than those who were more secure.
"Sexting is a way to avoid intimacy," Rob Weisskirch, professor of human development at California State University Monterey Bay in Seaside, said. He was not involved in the new study.
"These findings reinforce that sexting isn't' a behavior that people who want healthy relationships are going to engage in," Weisskirch told Reuters Health.
It's not the lying, but the frequency of the lying, that is surprising, he said.
"One would think that by the time you're engaging in sexting, there would be some relationship established and you would want to be truthful with your partner," he said.
But sexting might in fact be a tool for people who don't want to commit to relationships, he said.
"People could be lying about this a lot," Drouin said.
"People just need to not think that every time they want to sext, their partners always want to," Drouin said. "They may just be doing it to make someone else happy."