An Arkansas Middle School teacher has apologised after accidentally showing her pupils a home-made sex tape.

The explicit video showed the female teacher “performing sex acts” on her fiancé, KARK-TV reported.

She said the steamy video had got mixed up with her lesson notes.

The incident happened last week at Forest Heights Middle School, Little Rock. The school has launched an investigation.

Parents of the teenage students are in fury and are demanding answers.

One father, Nicolar Tolerson, told KARK-TV, “(My son) says she was performing sex acts. My heart goes out not only to my son, but other kids in the classroom.”

Tolerson said he wanted an apology and “something done.”