Important question is whether this is meant to imply that Lacus remained virginal maiden, or that the couple quickly experienced bed-death and estrangement?
>>23477510
I have no real basis for this, but I imagine Kira would be experiencing frequent nightmares due to PTSD, and may have wanted his own room to avoid worrying anyone.
>>23477773
Having superhuman strength and strangling a child in your sleep is worrisome.
That said, I don't think the writers were necessarily thinking that, but PTSD is in fact, a hell of a thing.