User blog comment:Oppaichan/Rito and Lala still engaged?/@comment-1290686-20140107041924/@comment-3965848-20140107091748

It's true that Rito loves Haruna more than Lala, she herself knows that, if they weren't engaged then she would have just   let  Rito and Haruna be together, she brought out her idea of polygamy as an alternate solution for him to be with Haruna while still engaged to Lala.

Gid would have probably taken her back to thier planet and destroyed the Earth if the engagment was canceled. If Lala's memory erasing invention did work, she woulden't live with Rito anymore, meaning she might have had her own place to stay and yet she still lives with him like she did before.

As I said in my earlier statement, in chapter 162 Peke said " when  they get married" instead of  if, so the marriage was still being planned even at that time.