Complex sentence: Behind her back kids, and even Mr. Weatherbee, will constantly talk about her "exotic" dishes and how they taste like rubber or glue, but they know better than to criticize if she can hear them.
Split into simpler sentences: Behind her back, kids, and even Mr. Weatherbee, will constantly talk about her "exotic" dishes and how they taste like rubber or glue. However, they know better than to criticize if she can hear them.