今度だけは

just this once

→ 今度
phrase Rare #44,579
just this once Emphasizes that this is an exception or that this occasion is different from others.
JA: 今度だけは許してあげる。
EN: I'll forgive you just this once.

今度だけはスーは時間どおりに会議にやってきた。

This time, Sue actually showed up to the meeting on time.

だから―今度だけはお願い

So, please—just this once.

— Departures (2008)

今度だけは遅刻を大目に見てやろう。

I'll let you off for being late this time.

今度だけは正しい

This time, at least, it’s right.

— ピエロがお前を嘲笑う (2014)