expression
unintentionally; in spite of oneself; though one didn't mean to
Used when someone does something they didn't intend, often with a nuance of regret or self-reproach. Common in set phrases like 不覚にも笑ってしまった (I laughed in spite of myself).
不覚にも涙が出てしまった。
Tears came to my eyes in spite of myself.
不覚にも彼の冗談に笑ってしまった。
I unintentionally laughed at his joke.