A special education teacher got a sweetheart deal while admitting to having drugged-up sex with a 16-year-old student at her parents’ home at least a dozen times. 

Michelle Mercogliano, 36, was sentenced Friday to just 15 months in a Pennsylvania state prison after pleading guilty to institutional sexual assault and corruption of minors, the Chester County District Attorney’s Office said.

“As part of the plea, Mercogliano admitted that she had sex with, and provided marijuana to, a high school student,” the DA’s office confirmed of the now-fired Conestoga High School teacher.

The now-fired Conestoga High School teacher bought medical marijuana for the boy around 15 times from a Phoenixville dispensary, police said in their initial complaint seen by WPVI.

They would then “smoke marijuana together and have sex, usually in a bedroom at her parents’ residence,” the complaint said — saying it happened around a dozen times and almost always at her parents’ home in Wayne.

The boy eventually told his sister about the disturbing trysts, which she then informed her parents about, leading to the teacher’s arrest in April last year.

As well as the short time behind bars, Mercogliano will have to complete more than 6 1/2 years of probation — and register as a “Tier II sex offender” for 25 years. She has forfeited her teaching license and cannot work with kids while on probation.

“Parents and students should be able to trust their teachers,” DA Christopher L. de Barrena-Sarobe had said last year when the perverted educator was first arrested.

“The defendant broke the law and destroyed that trust. It will not be tolerated.”