Names

We were doing an activity where the students had to tell me the first sound of the words I said.  Here is where it went awry:
Me: "What is the first sound in the word flor?"
Class: "FFFFFFFFFFF!!!!!!!"
Me: "Yes! Great!"
Student 1: "My mom's name is Flor!"
Me: "Yes, that's true.  OK, what is the first sound in the word burro?
Class: "BBBBB!"
Student 2: "My mom's name is Burro!"
Me: "Umm...no...I'm pretty sure your mom's name is Megan."
Student 2: "Oh yeah.  I forgot."

(burro means donkey in Spanish)