smirk|smirked|smirking

他脸上露出得意的笑容，好像知道了什么秘密。

He gave a ___smirk as if he knew a secret.

他得意地傻笑着，好像知道了什么秘密似的。

He ___smirked smugly, as if he knew some secret.

他露出一个狡黠的笑容，好像知道什么秘密似的。

He gave me a ___smirking grin, as if he knew a secret.