" To spill the beans" - to let out a secret.

“泄露秘密” ——泄露秘密。

But he resolved to cure at once her tender feeling, if it existed, by letting out a secret which would inflame her dignity against the weakness.

但是他决定立刻治愈她的温柔，如果她有的话，通过说出一个秘密来使她的尊严对抗弱点。