@fanghue Here's what I speculate is gone happen.
1. She sleeps with gen. I doubt this one personally, even she insists, he ain't gone agree whatsoever, unless, of course, she threatens to tell his father about him telling reiji about what's been happening between his father and Rejii's mother.
2. She kills Gen, and maybe his father. At this point, I kinda see this one happening. Why? Because now that Reiji is longer associated with his mother, she can stop sleeping with Gen's father. Meaning she's no longer forced to go this damn building and sleeping with, what I will assume, an ugly bastered.