expression, adverb taking the 'to' particle
as if it weren't already enough; to add insult to injury; on top of everything else
Used when something excessive or overdone is piled on top of an already sufficient or overwhelming situation. Often carries a tone of exasperation or dark humor. Frequently appears with と or as an adverbial phrase.
散々待たされたあげく、これでもかこれでもかと追加料金を請求された。
After being kept waiting forever, they charged me extra fees on top of everything else.
彼の自慢話は、これでもかこれでもかと続いた。
His boasting went on and on, as if it weren't already enough.