Look for Oyster’s “Yagate Azenaeru / Becoming Twisted”. It’s a story I’ll post in full after the last chapter. The two women are sisters who have been abducted. The story follows their mind break, and the man who comes after them in this chapter is Saki’s (the red head’s) husband.
Fair warning, the author Oyster pushes fetish works. That includes rape and mind breaks, but virtually any other dark mind game that can follow it. I recommend only checking it out if you’re genuinely curious and won’t just be sick from it.