[His retort forces her eyes up to him, and she can but watch as he tears off on his own, leaving her behind and stunned. It's not so surprising, just... she wasn't exactly prepared for it, after what they had discussed. But she doesn't follow after, to ask why he would do that when they had already discussed it.
Probably because it hurts. It hurts and bothers her to be hurt and bothered by this no matter how she tries not to be. To have something precious right in front of her, but unable to accept it because she must continue on to something much more distant. To hear him say such things and know he means it when he knows this is her situation.
She thinks it would hurt far less to hear him say Lina is more important to him, period]