Substitute Teacher's Name

Little Johnny was walking down the hallway at school. When he reaches his classroom he looks inside and sees a sub instead of his regular teacher.

Johnny sits down and the teacher says,
“Now students, my name is Ms. Prussy. Not the other word, this word has an r after the first letter.”

Johnny started laughing. An hour later he forgot her name and said,
“Your name has an r after the first letter -- is it Ms. Crunt?”