In place of a stress ball, to grab and squeeze a girl's breast in order to relieve stress. the girl's breast will therefore experience the stress. the amount of noise created by the girl's squeal indicates the level of stress. In this way the stress breast can also be a stress test.
If stress exceeds a breast's capability, first try grabbing both breast's at once, and if that doesn't work, move on to a larger size.
I walked into school today angry and so I needed a stress breast. Jess was perfect. When I grabbed her tits she screamed so loud, the preschool next door was disrupted. Apparently, I was pretty angry.