I believe he meant that they filled in both emptiness by being together. Both of them had an unrequited love when they met each other. Knowing the pain of being in unrequited love and gay, they seek comfort from each other.
If I were Hazuki, I ain't accepting him no more. When he denied Hazuki in right upfront someone else, that was the end. Cheating or deceiving is always a choice and having an excuse just to justify it is bullshit. Hazuki deserves more.
I guess we'll see each other the next 2 years hahah.
And maybe we could discuss the end in about ten years ahahahahah