This story was pretty good, I would have loved to know a little bit about MC's past (you have to have a certain kind of past to see how the person you love is doing it with someone else, even more so when he idolize her, that's a whole other can of worms), but everyone got an ending that fulfills their wishes.
'my truth' and 'your lie'. MC's truth is that he loves Iida but he's a cuck and needs his fetish so he can function with her. Iida's lie is that she actually cherishes him a lot, but in order to have more, eh, intimate relations with him, she needs to lie and tell these fabricated stories to get him going. But that is my humble guess.