@lfscruz: Because during the flashback, Kazama's mom called Takao's breasts a "great set of strap jacks" (in reference to her size and how well they are emphasized when a strap (purse, bookbag, etc) is between them.) in the previous page.
Everyone else noticed her "strap jacks" but cut themselves off too late, so they made some bullshit up to keep from Takao finding out and offending her.