I have to say I completely not understand the entire chapter. I do not understand Ten's thinking or action. I literally have no clue of all the conversations involving her to herself or others. I am at a lost. I do not know what did she mean when she thought she screwed up. I do not know why she thought Lulu would hate her. I certainly have no idea about the entire conversation between she and her classmate. I have it twice and I still do not get it. Maybe someone here will make a comment and help me figure it out. Otherwise I guess I have to wait until the next chapter to have a better idea.
The whole premise of the story is that Lulu fell in love at first sight with Ten. When she criticized the guy that confessed to Lulu for basically falling in love with a complete stranger, she indirectly invalidated Lulu's feelings too. We know Lulu feels insecure about it, and Sakuya is making her think she's been forcing herself on Ten, so that remark made things worse.
TL;DR: Lulu fell in love at first sight with Ten. Ten doesn't believe in love at first sight and accidentally invalidated her feelings. Sakuya is taking advantage of the situation, because if she can't have Ten, she won't allow anyone else to have her.