A Round Rock assistant teacher and coach is wanted for allegedly having a sexual relationship with a student.  

Round Rock Police say a Stony Point teacher's aide and coach secretly carried on a relationship with a student on and off the clock.

Police say Noah Byrd, 25, started a relationship with the 17-year-old student in October. The student said Byrd would send her text messages in class.

"They were explicit in sexual nature and were concerning to a degree even beyond that as if that's not bad enough," said Round Rock police officer Eric Poteet.

According to a court affidavit, the relationship was also physical. The student said Byrd picked her up after a football game in early November and they had sex. Police say when administrators questioned Byrd about the relationship Wednesday, he walked out of the building and hasn't been seen since. Police have issued a warrant for his arrest.

"Clearly we hope that anyone has information about Mr. Byrd's whereabouts,” said Poteet.  “We would like to know we would like to apprehend him."

School administrators hope something can be learned from this.

"We'd like our parents to talk with their children about what is an appropriate relationship and what is an inappropriate relationship and the importance of reporting right away," said RRISD spokeswoman Joy Lynn Occhiuzzi.

As for police, the investigation isn't over yet.

"There is still much work to be done. If not just to back track the year that he was employed just to make sure there wasn't anyone else he was involved with," said Poteet.

Byrd is no longer employed at Stony Point. He faces a second degree felony charge of improper relationship between educator and student.