Tā shùnkǒu shuōchūle mìmì, zìjǐ dōu méi yìshí dào.
He blurted out the secret without even realizing it.
Tips
usage
顺口 has two main uses: (1) describing text or speech that sounds natural and flows well; (2) saying something casually without thinking (顺口说出). Context determines which meaning is intended.