Late nights, playin' in my darkened playpen [up inside my arms]

The story:

The first 30 times I heard this song on the radio I was convinced that it said "playing in my darkened playpen." I was really worried about Mariah Carey wishing she was a baby again, and starting a baby fetish. Kinda terrified, until I looked up the actual lyrics on the internet...I still can' hear the real lyrics when I listen to the song.