Calculation
Ferb walked into his room to hear the sound of his brother madly writing at his desk. It was not an unusual sight to see the red-head so focused at his work station, but what did seem out of place was the fact that it was a Saturday and neither of them had homework. No blueprints were in sight either, which caused the Brit to raise an eyebrow.
After a minute of listening to the sound of graphite on paper, he spoke up. "What are you doing?"
"I'm calculating," Phineas replied.
With a puzzled expression, Ferb replied, "Calculating what?"
"Love." His face turned a slight shade of red at the statement.
Ferb couldn't help but chuckle a little at his remark. "You don't calculate love, you feel it."
"Oh," Phineas whispered as he furiously erased the paper.