Out of (much) interest, have you considered a Filia x Samson fantasy - the exact fantasy you've described but with Filia as the victim of Samson. Basically, Filia is frustrated - very frustrated, but for whatever reason (prudishness, embarrassed, or just because she has a monster on her head seeing everything she does) is unwilling to do anything her frustration. Samson, being connected to her, can sense this, feel it too, and eventually snaps, restraining her and starting to forcible 'deal' with the frustration. The fun part being that Filia can feel everything Samson is doing to her, both with her own body and with his, all at once.
Just a thought.