言っとくけど

just so you know

→ 言う
phrase Uncommon #10,572
just so you know A casual contraction of 言っておくけど, often used before a frank remark, warning, or clarification.
JA: 言っとくけど、今日は早く帰るよ。
EN: Just so you know, I’m going home early today.

言っとくけど-お腹に赤ちゃんがいるのよ

Just so you know, I'm pregnant.

— Carandiru (2003)

念のために言っとくけど、友達なだけだよ。

Just so we're clear, we're only friends.

言っとくけど志願したわけじゃないんだぜ

Just so you know, I didn’t volunteer.

— イノセンス (2004)

言っとくけど、あなたのために説明したのよ。

Just so you know, I explained it for your sake.