I don't like Chris, too, but seriously why nobody is overthinking Anna's behavior as well?
Chris wearing just a towel went uninvited into her bathroom (a very private space), while she was doing her morning routine. During his whole shower, Anna stayed in the bathroom in her underwear, while chatting with him. There is an inner monologue, but not very convincing, because the situation is very different to growing up with brothers and having to share a bathroom. After all Chris is not one of her siblings... It sounded more like a justification for herself to stay and tolerate Chris' intrusion into her bathroom.
Seriously no woman (being loyal to her husband) in real life would do so - being stubborn or not doesn't matter in this situation. It's just not plausible.
A loyal woman would have thrown Chris out of her bathroom asap (by becoming really angry, shouting at him or even threatening to call the cops and to have him thrown out of her house as last resort) or would have left the bathroom herself immediately.
The little inner monologue about her plan to hide, that Chris' intrusion makes her uncomfortable is not convincing, too. Because she is very well entitled to feel uncomfortable in her private bathroom wearing underwear only (the situation is definitively not the same as wearing swimwear in a public bath), while another man showers, who is constantly flirting with her and makes no secret about his desire to have sex with her.
She pretends to dislike it, but she lets all of it happen. Secretly Anna is enjoying the attention of the opposite sex, because her ego longs for it as a narcissist. It's also not just Kendra's doing... If Anna had a solid personality, Kendra would have no chance to manipulate her. (Best example is Marvin, you can reject his advances as player, but after the lunch with Kendra Anna considers teasing him.)
Since I believe in self-responsibility above all else, I think Anna is more to blame for what's coming than her seducers, who are simply trying to fuck her.