Yeah, this story got most things wrong. Considering it’s apparently not going to be a typical NTR story, it would be weird to revert back to that after chapter 8. The development of Lily and Anna’s relationship was poorly done, leaving almost no reason for readers to want them to become a couple. Especially after that time-jump.
It doesn’t seem like the author intended it, but Lily comes off as very stupid and horny. Rose was supposed to have seduced and manipulated her, but Lily just seems foolish and completely indifferent to Anna and her feelings. You can't change that impression with one scene in the second-to-last chapter. This author seems allergic to the concept of build-up, always jumping from 0 to 100.
So that's just it? ¯_( ° ʖ °)_/¯ You'll go to Rose because Anna didn't want you, but now that she's said that she wants you, you'll go to her? What pettiness! (and horniness) And c'mon Anna, you deserve better, girl!!!