The Sweet Side of The Bad Boy.
Selena thought she knew love; but she was so wrong.
It was like a balloon being held up against a sharp object. You can see where it's caving in, yet it refuses to burst until you've driven it straight through. Selena's feeling that way, about the pressure, about the relationship, about everything. But she can't do anything about it, or else he'll do something unpleasant to her.
Then, there's Zero. You'd never really hear peep from him. So, imagine Selena's surprise when no matter what they do to avoid it, they continue to come into contact with one another. Fate continues to place them in each other's path.
There was only one explanation for it, really.