So Kristen Kringle is (basically) murdered again. Only in Gotham folks .
And Penguin obviously didn't think that through, since there's no way Nygma is going to rest until he figures out what happened and we know he's smart enough to do it. That being said, Oswald's entire reaction to Edward's relationship and his attempts to undermine it were pretty hilarious, right up until he had her killed (which anyone should've seen coming).