wickedly

The little boy grinned wickedly before hiding his sister's favorite doll under the bed.

(Chinese) 那个小男孩调皮地咧嘴一笑，然后把妹妹心爱的娃娃藏到了床底下。

The villain laughed wickedly as his grand plan finally began to succeed.

(Chinese) 当反派的宏伟计划终于开始成功时，他恶毒地大笑起来。