The one on the song she sings with John Mayer on his album about how “you love who you love.” Mmmhmm .
A transcript of the "love giggle" part of Sirius XM's Morning Mash Up:
Nicole Ryan: Did he tickle you or did you mess up?
Katy Perry: I think that's just a love giggle. It's like the ones that Mariah Carey had in 1990 and stuff like that. Yeah I think I was going for that, I think I was just so happy…I love that song, you guys will hear it soon, all you listeners.
Nicole Ryan: I like it when people leave in those little outtakes…
Katy Perry: Yeah it's very humanizing, it's like the real moment, you're catching the real moment there.