Disclaimer: I do NOT own BtVS or Evanescence's Imaginary.
Imaginary
It was more than Jonathan could ever understand. A bond. A quantity of pain so strong that numbed Andrew's heart beneath the sternum. And he became addicted shortly after Warren began his charade. He felt the need to get it so that he could soak his senses in it.
He never experienced real love. But he knew that this was the closest thing to it he'll ever get, and Warren complied, in order to keep him close. And now Andrew sees the truth, but through obscured glass. He'd never let himself dive headfirst into reality. He'd seek protection of heart in his own fantasy world.
And maybe that's why everyone in the Summers' house avoided him.