shelf duster

A woman brushing off crumbs accumulated on her shirt around the topside of her breasts. Usually associated with a full-bosomed woman with a nice upper shelf.

Shelf dusting -engaging in said activity.

"I love watching a shelf duster do her business after a little snack. They should make shelf dusting videos!"
"After eating the crusty French bread, Lizzy tidied up her black t-shirt with a quick bit of shelf dusting."