Pleasant Valley School District has placed a custodian on leave on administrative leave after he was charged with sexual assault of a 16-year-old girl.

The district board of education meeting held an executive session Thursday for "purposes of personnel, matters including, but not limited to, performance and/or discipline, negotiations and legal issues."Superintendent Carole Geary said this action was taken "(as soon as) the school became aware."Robert Pini Jr., 31, of Effort, is charged with felony counts of institutional sexual assault of a minor and unlawful sexual contact with a minor; endangering the welfare of children by a parent, guardian or other; and 16 misdemeanor counts of corruption of minors.Also a junior high football coach, court documents say Pini admitted to meeting the 16-year-old girl for sex at least 15 times at various places in Chestnuthill Township.He was arraigned before District Judge Colleen Mancuso, Chestnuthill Township, and freed after posting $25,000 bail.Geary said Pini, who worked the night shift, is on "administrative leave pending the outcome of the investigation."It's not clear how long Pini has worked for the school district, but he has been a volunteer football coach since at least 2010.Pini knew the girl's age because he was at her 16th birthday party, according to an affidavit of probable cause filed by Detective Wendy Serfass.Pini's actions came to light when the girl told her parents about the relationship.Police learned of the matter on Sept. 27.That's the day the girl's father called Pini, who admitted to having had sex with the girl over the summer, and to having given her alcohol at least three times.After the phone conversation, Pini texted the girl's father, saying "I am sorry for what I have done. I don't know what you are going to do. But all I can think is that I just lost the biggest part of my life. I am sorry again. tell (the girl) I love her and to smile. Sorry again for what I failed to do. I guess this is a goodbye."It's not Pini's first brush with the law.In October 2009 he was charged by state police at Fern Ridge with disorderly conduct after he stood in the parking lot of the West End ambulance building, shouting obscenities because someone inside the building would not talk to him, according to court records.Pini pleaded guilty to the charge and paid a fine.Sharon Stanley contributed to this report.