Girl, We read the same story, the conclusion people take varies person to person. If you think she naive my opinion is she stupid the reason why she easy to manipulate because she already catch feelings the first time they met, even so she dares to go back to that house. I never said that guy is innocent, but if that girl is my girl i definitely won't take it as she just being naïve
Second, your understanding of values and morality are different from mine, if you thinks cheating is okay, I'm not, especially when things get physical like that and the boyfriend being also very sincere. Third, idk if you notice but this is a fictions character with a fiction story i bet the author also like every kind of reaction from a reader. Me 'slut shaming' her knowing what happened in the story, but if you afraid i slut shaming people in real life you can trust me, i won't and never did, because idk their story nor did i want to associate with them.
1. First time they met he flirting and gave her his number knowing she is his brother's girlfriend
2. Second time they met he hug her and whispered sweet nothing
3. She goes back to their house knowing that man there and knowing how dangerous he is (she could just give that umbrella to her bf)
4. She step in the house knowing her boyfriend not there
5. Then she slept with him (she said no but didn't try escaping?)
Idk know if I'm too intelligence or what but the first time it happened pretty sure everyone knows what it could lead into, despite that she still stepped in the house and you still think she naïve? It scream stupidity to me.
PLS
Take a moment and try to reverse the gender, if the role was a man are you still gonna say it was manipulation? What trick did he do again? How naïve you can get to not realize anything untill u get to the 5.

1 story; Dang SLUT gurl