kinky fantasy, hypnosis, accidental syscovery, "you"
You give your sub a trigger to help her explore her dominant side. It works surprisingly well, but she stops talking to you after that without saying why.
Months later, you finally hear from her, but she introduces herself as the trigger word you gave her. She's ready to forgive the disruption you caused the two of them(?), but you'll have to become her pet first. She might even let you play with your old sub again, if you're good.