i feel like this is a bit of a reach and kind of delusional, but please hear out my vision:

post-canon mithrun who was re-discovering her (sexual) desires and tried to masturbate. but she already forgot how to want such things or even how to touch herself. so (imaginary?) wakami offered to help. telling her how to feel, where to touch, what felt good and what she would like. "I'll tell you how you feel, so let's feel good together~"

waow.....thank you for your time