In "Whistle", Peppa, sad about not being able to whistle, calls Suzy:
Peppa: Can you whistle, Suzy? Suzy: No. Peppa: [pig snort] Oh good! I mean, that's sad if you can't whistle, but good, because I can't whistle. Suzy: What's whistling, anyway? Peppa: You put your lips together and blow. Suzy: Like this? [performs a long whistle]
[Peppa immediately hangs up.] Suzy: Hello..? Peppa?