https://www.amazon.com/dp/B0BWWMRCX9
Lydia is put off at first by Cameron's rough and somewhat cruel treatment of Keely, but the tiny woman keeps begging for more brutal punishment from her SSBBW lover. Eventually, Lydia is convinced to join in and finds extreme levels of passion and satisfaction that she had never expected.
Joanie's quest to supersize her body is an amusing distraction for Lydia as she laments falling so far behind Cameron. However, being looked upon as a mentor, idol, and using unconventional means boosts Lydia's hunger. She soon passes a whopping 800 pounds and is ready to face Cameron again on the scales.
This is the fourth entry of a series.