05/09/2013 02:52 pm ET

Marlene Mints, Sex Ed Teacher, Accused Of Sexual Relations With Students

A Texas health and sexual education teacher is accused of having sexual contact with a 13-year-old male student after he told her there was something wrong with his penis.

Marlene Mints, 31, is now on administrative leave from her position at Bessie Coleman Middle School in Cedar Hill, MyFox DFW reports.

The investigation began in late April, when a coach at the middle school was driving some students home, and one of the students brought up that he'd had sexual relations with Mints, according to an arrest warrant obtained by WFAA.

The boy, who was a student in Mints' sex-ed class, claims he was texting with Mints in January and he told her he was having a problem with his penis, and she replied she would have to see it to know what was wrong. The boy says he then went to the school, where Mints performed a sex act on him.

Investigators say Mints also had sexual relations with a high school senior. Mints allegedly texted the senior asking "if he liked white girls," then invited him to her home where she performed a sexual act on him, according to CBS DFW.

Maggie Roberts, whose niece goes to Bessie Coleman Middle School, told the station that she is "very disappointed and very surprised" at the allegations. Roberts said Mints is "a great teacher. Always friendly, smiling, willing to help."

Mints has been charged with aggravated sexual assault of a child and two counts of improper relationship with students.