When Brittany Heard the means she got curious then she walks towards Shun Yu's Room, then to her surprise and shock she discovers 4 Girls and Shun knew the 4 girls because it's the 4 slaves she 1st knew.
And she's so shocked that she can't process the situation, her mind was so in turmoil her body can't even leave the room she didn't know why they were trained to fight but on the other fact that they are not trained for sexual orientation,
Then she smells a fragrance that she's somewhat recognized, although they are trained to fight Recognizing poisons and Fragrance that can harm or give your body weak points was being taught at their Agency, and she recognized the Aphrodisiac fragrance that she smells on Shun Yu's entire room so that's why she realize it again that her body was burning with desire.
Her body was burning with desire to join but her mind was declining the fact that she didn't want it, she's not used to it she hates it.