Parents at a Pennsylvania middle school were outraged this week after their children were assigned a "50 Shades of Grey" word search puzzle to complete. 

The fetish-themed worksheet asked students to find words such as "bondage," "submissive," "paddling," and "spanking."

James Carter, the parent of a Monessen Middle School eighth-grader, said the assignment was highly inappropriate. 

"I asked my son who passed it out, and he said the teacher passed it out," Carter reported. "I don't think this is what they should be doing in the eighth-grade level."

The father said that school officials refused to answer his questions when he confronted them about the word search on Tuesday, but the issue was addressed at a school board meeting that night. 

"We just learned of this issue yesterday," solicitor John Toohey told attendees. "An investigation will occur."

The board declined to comment on who distributed the puzzles, citing personnel issues. 

Board member Roberta Bergstedt, who was not at the meeting, told reporters by email that the worksheets were given to students accidentally. 

District officials declined to comment on whether any teachers or staff members were disciplined for the alleged mixup. 

The controversial film "50 Shades of Grey" is based on the best-selling book by E.L. James. The text and movie delve into the world of sadomasochism, and the film narrowly avoided an NC-17 MPAA rating.

"50 Shades of Grey" will be released on the day before Valentine's Day, February 13.