Jellybean Starts With K

Ben is learning what letters make what sounds, so he likes to go around listing words and then saying what letter they start with. Sometimes he gets a whole bunch right in a row, and sometimes he gets a whole bunch wrong in a row. This morning on the drive to preschool he was on a losing streak.

"Jellybean starts with B!"
"Nope."
"S!"
"Nope."
"Y!"
"Nope."
"K!"

"Jellybean," I enunciated carefully for him. "If it started with K, it would sound like Kellybean." I couldn't see him since I was driving, but he sounded perplexed.
"Kellybean? Can we eat that?"
"I was just joking honey. There's no such thing as a kellybean."
"But would it taste good?"
"Nevermind..."