To be honest, I'm not surprised at all. Ever since he was raped, he only saw interactions with women to revolve around sex. :/ god demnit Punpun. You really need to go to therapy.
Also, Aiko again said "If you love me, then I love you too." just like she did as a child. Is she incapable of love?
When she was a kid, it made sense that she wouldn't understand what it means to be in love. But saying it right now seems like she is completely unable.
I was also afraid that he impregnanted her, what with Sachi having an abortion and all. They really shouldn't be together, the only ending I see her manipulating him to kill the mother.