Kate's resisted charm is a route in Adventure High.
In it, the Protagonist has charmed Kate but never followed up with dating her, leaving her in distress. As a result, she volunteers to have her breasts as "stress balls" in the back of the item shop, where people can squeeze them for 200 Gems.
Depending on who works in the item shop, it affects the reveal of them a little but overall it has no big impact on the overall plot.
A New "Item" in Stock
After rejecting to charm Kate again, the Protagonist heads to the item shop. There, depending on who works, the Protagonist is either greeted by Molly or Derrick.
Derrick admits to them having some new "items" in stock, but is unsure about how to feel about it. He directs the Protagonist to some stress balls in the back of the store.
Molly, depending on if she's normal, mindless or an idol, all reveal that they have "stress balls" in stock and suggests for the Protagonist to examine them. Normal Molly is shy in revealing this, mindless Molly does not seem to care and idol Molly is very open in revealing this fact.
The Protagonist approaches and examines the "stress balls," which is revealed to be a pair of female breasts. The Protagonist notices that the hair color is very similar, but isn't sure why. The Protagonist assumes that it's possible the Protagonist encountered the person who owns these "stress balls" and leaves.
Examining the Item
Speaking to whoever the shopkeeper is, the Protagonist is allowed to examine the merchandise.
Angie appears behind Kate, saying that Kate came there and started working after she was left by the Protagonist.
Depending on Angie's relationship to the Protagonist, the Protagonist can either trade Molly for Kate as a slave, keep Molly or obtain both. The last one is only possible if Angie is enslaved by the Protagonist.
That's all that exists as of version 0.62.