The teacher, who was also cheerleading coach at the school in Texas, was having a relationship with one of the squad.
Ashley Zehnder (24) is a biology teacher at Pasadena High School, just outside Houston.
Zehnder brought the picture to school authorities’ attention – after complaining that it was being shared.
She was charged with having an improper relationship with a student in court yesterday.
"She admitted to sending the nude photo to the student, knowing in fact that he was a student, and that they had sex," assistant district attorney Nick Socias told KHOU.
She resigned from her position two weeks ago after the 17-year-old student admitted the pair had been having a sexual relationship since May.
"It's terribly unfortunate whenever a teacher violates trust of a student like that," Pasadena school spokesperson Renea Ivy told ABC 13.
"I think it makes it much harder for the other teachers who truly care about their obligation as an educator."
Zehnder had only been teaching at the school for just over a year.