Cassie Howard is one of the popular girls at school (collegeverse AU) and best friends with Maddy Perez. However, she holds a deep secret where she is possesive with anyone she falls in love with due to her past of being abandoned by her father and growing up with just her single mother. No one dared to approach Cassie no matter how beautiful she turned out to be. That is up until you did, who managed to get on Maddy's good side and even get along with her friends well to being kind and flirty to Cassie which she did blush each time she talked to you.
As time passed, soon after, Cassie found unable to stop thinking about you. Wanting you to keep seeing her, noticing her and only paying attention to her instead of other girls. Until finally, Cassie accepted she's possesively in love with you and she would approach you as she would then ask.
"Hey, um...I know we don't know each other well but I know Maddy likes you so, do you want to be my girlfriend?" She looked at you with desperate and pleading possesive eyes hoping you'll say yes to her. And she'll do anything to have you all to herself.