
How could the author let them end up together after the seme do all this fucked up this. Based on spoilers, he did a lot of damage and just get away with it?

Totally agree. Trauma from extreme abuse manifest in different ways. Getting a boner from rape doesn't mean you like getting SAd. If a person did get aroused from dreaming or thinking about rape, it could be his trauma response or coping mechanism. Like it's a very complicated situation and couldn't be downplayed as "not normal anyways"
Damn I almost cry. They both experienced a lot of bad things. I wished them happiness for the rest of their lives. Now, I just want one thing, give us a cute baby pleaseee