I think most of my upset with Momo was for not realizing that Kaidou would take it more seriously, and treating it so casually when Kaidou DID react badly.

Infidelity isn't something that gets dealt with in a lot of fanfiction, which is a pity because it's such an interesting subject, with so very many nuances. I really liked that story, personally. I think you did a good job of it, though it did seem a little deliberate on Momo's part at the end.