Communicate. Talk to him about it, figure out how to handle things between the two of you, from both sides if that occurs. What I mean is, ideally if it did start happening, he would need your support and you would need his in different ways. YOu would need a lot more reassurances that it wasn't you, and he might need support in how the ED itself makes him feel inadequate or whatever other feelings it brings about. head it off before you reach the obstacle and be in agreement on how you both will support and love each other if such a thing happens again.