expression
it's no big deal; it won't hurt; it's not like it's the end of the world
Colloquial phrase used to reassure someone that doing something won't cause any loss or harm, often implying 'you have nothing to lose' or 'it won't cost you anything'. Literally 'it's not something that decreases'.
謝るくらい減るもんじゃないでしょ。
Apologizing won't hurt you, you know.
ちょっと聞いてみるだけなら減るもんじゃないよ。
Just asking won't cost you anything.