What is there to understand? The guys consider themselves straight. Just like 80% of other yaoi...
Well, in 80% of the other Yoai, we don't have to *see* naked female body parts. They can talk about it, or it can happen off page, which is fine. To me the Yoai tag means the sex scene involve naked male parts. If I wanted to see naked women, I'd read yuri or hentai. Call me rigid, but if it's yaoi, the sex scenes that exist should involve naked men.
I'm still reading in case the story moves to a better place, but I will never like the woman.
Even if it's not all yaoi I'm okay with reading it. I'm down for a complex story. Most yaoi are only about the sex so it's nice to have an actual plot. This manga feels like a real gritty world where most yaoi is very throw away and copy past. If people want more sex scenes there are always a thousand other mangas that will satisfy there needs.