The best line by Fields isn't spoken - it's where he brings a adorable sweet innocent kid - Shirley Temple, I think - to a soda fountain, and when they're served their foaming floats, he turns and blows the foam off the top as drinkers used to do with beer.
rich-joy, why are you looking for this particular line - is it to find what song he's talking about? A bit of context would help in the search.