Love
Stockholm syndrome? Perry didn't believe in it. Why would anyone fall for someone who was holding them hostage? It didn't make any sense. He was captured by Doofenshmirtz every day, and Perry had yet to fall for that bumbling idiot.
At least, that's what he kept telling himself.
"And, that's why I created THIS!" Perry was jolted out of his thoughts by his nemesis's exclamation. "Behold! The mashed-potato-inator!"
Perry rolled his eyes, trying his best to ignore the butterflies in his stomach.
"Now, Perry the Platypus, tremble as all the potatoes in the Tri-State Area become mashed!"
That was his cue. Perry kicked a hole through his potato-shaped trap.
Doofenshmirtz looked at him in surprise. "Perry the Platypus, how did you escape?"
Perry punched him in the face. The punch was softer than usual. Perry wondered why. Why didn't he hit Doofenshmirtz the way he normally did? And why did he suddenly feel guilty about hitting his nemesis?
He couldn't, could he? No. Absolutely not. A platypus loving a human was one thing, but a platypus loving his human-nemesis?
It couldn't happen, could it?