TA103 Small Adhesive Tapes come a Dozen to a Package.
These will help anchor the breastforms from moving.
FDA Approved Safe to the skin and polyurethane shell. Please be careful, however, to avoid using the tapes with other adhesives as there may be a chemical reaction that may occur.

Remove carefully from breastforms with liberal use of adhesive remover. Then wash breastform with warm soapy water.