あんた、目が泳いでるよ。

[phely]

I came across this one on level 9, while studying the kanji ‘to swim’ = 泳ぐ
I can’t understand this interpretation thought

あんた、目が泳いでるよ。
hey, your eyes are shifty.

Thanks!

[Belthazar]

It’s an expression.

[phely]

Thank you, the link is a bit too complicated for me yet (no grammar background at all).