Place it as the reaction beat right after the cute reveal in your edit, then follow it with a gentle cartoon pop for punctuation. For a longer bit, precede it with a brief drumroll build so this confession lands as the payoff.
Über diesen Sound
This clip is Fluttershy speaking the sheepish line 'I couldn't help myself. They're...' in her gentle, high voice over about five seconds. It feels sweetly guilty and endearing, like an apology for finding something too cute to resist, and that soft delivery makes the admission sound sincere rather than dramatic.