"So long my luckless romance, my back is turned on you.
Should've known you'd bring me heartache. Almost-lovers always do."
–A Fine Frenzy, "Almost Lover."
She's not upset it's over. The real pain comes from seeing him pretend it never happened at all.
She expected he would banish her entirely. But he hasn't. She has no place in his bed or his heart. She belongs at his right side. Still trusted but no longer cherished. Still, she clings to him secretly even as she opens her heart to another.
She wants to leave, thinks her new husband can repair some damage and help her forget. He won't let her go though and won't take her back either. She has no choice but to let him break her heart again.