A girl was wearing this shirt to school?

Question:

A girl was wearing this shirt to school?

It said " Save a Horse Ride A Cowboy" and its a song. I havent heard the song before but the teacher told her to go take it off. Whats so bad about what the shirt said?

Additional Details

3 weeks ago
I didnt know which catagory to put it in so I putted it in this one.

Best Answer - Chosen by Asker:

It was because it was a sexual reference and therefore inappropriate. Very sad her parents let her wear it in the first place, my kid wouldn't get out of the house in that.