Serene thought of the days they spent talking about everything without hiding anything back from each other, especially he doesn't know how to hide anything from her.
she remembered ,her-chiding him, running in the garden, him- consoling her when she lost her last ice cream, Even when they are entering the teenage years promising not to have a girlfriend/boyfriend until 18.He told her"in the future, you can takeover my parents company ,while I play my favorie basketball". She thought she was special to him, may be they can bond in the future.
Even though she noticed his obvious changes, like giving up on his favorite basketball, working in his company, not liking spice anymore, even behaving so intimately with her cousin ,not even apologizing when she caught him ignoring her calls.
After all that she just thought maybe he has a change in affection ,not wanting to make Elena jealous when she got to know they are in a relationship. But her hopes shattered when Elena deliberately framed her, Even though Serene can easily solve that,she hoped at least he respected her and would help her as a friend. He supported Elena and criticized Serene all while knowing she is not the culprit.