There are applications for surfactants in which their tendency to foam is undesirable. For example, the cleaning action of modern washing machines relies critically on foam suppression.
Silicone fluids act as antifoams. Antifoams have a low surface tension, poor solubility in the medium to be defoamed. The particles (molecules) of the antifoam displace the surfactant molecules from the surface of the lamella and replace them with a new film of lower surface tension and lower cohesive forces.