I told you about it. You already forgot.

我告诉过你的，你已经忘了。

youdao

I'm still here waiting for you but you already forgot you've been here before.

我还在原地等你，你却忘了你曾经来过这里。

youdao

Or if he forgot to do it, he would make up a story saying that he remembered, but thought you would have already done it, instead.

如果他忘记取衣服回家，他就会编织这样一个故事：不是我不记得了，只是我觉得你已经把它取回家了。

youdao