[Eren has been trying to read Aubrey's lips this entire time, though he has no skill for it. He does catch what he thinks is a "don't know why" though, and it makes his heart sink just slightly; with what? Regret? Embarrassment, maybe? Mix them both together and you've got shame.

[He thinks again about Aubrey's cold, "I love you." He squeezes her hand again. There's this deep, compulsive desire to be alone with her. He's only felt something like that for one other person.]

That's what I'm talking about.

[Glancing at Armin.]

Our minds can shape the world around us. Whether or not we're in control is another thing...

The last time things went badly, ["Don't know why,"] my mind went to a bad place.

[His eyes are back on Aubrey's; an apology.]

That's what happened.