"I want to have your child."
Celestina blurted out what was in her heart all this while. From the moment she realized the true identity of Evan and Seraphina, she was feeling inferior, she felt a normal human like her wasn't worthy enough to have Evan, but now that she feels she has awakened a good soul and a really powerful ability lurks within it. She now feels somewhat capable enough to be by his side.
While Celestina finally felt she was slowly becoming deserving of Evan, he was having different thoughts inside him.
An orphan from a young age, he didn't even know who his parents were, even after being awakened he was still useless, bullied, mocked, and treated like trash his entire life, he finally has a place he calls home and people he calls his family, but even after all this he still doesn't feel deserving of them. It was the home of the previous Evan and the family of the previous Evan, he is just an impersonator.