I want to feel your foamy inside

The story:

While driving around listening to tunes, my friend accidentally verbalized the singing in his head (maybe cool for chicks, but not cool for dudes)! Then I contemplated the question, why are her insides foamy? Did she eat a soap-a-pia for dinner? The best part is that I don't remember correcting him. So, if you see some guy singing about foamy insides, say hello to my friend!