This term is used when wanting to talk about a kid who is being a little retard in public, while not offending them or the mother. The play on words is derived from the following:

Fabric Softner --> Downy --> down syndrome --> retard.

since it is no longer socially acceptable to call a kid a retard, or claim they have down syndrome; this term works well because it is perfectly private, and no one knows what the fuck your saying.