Let's keep to the subject, or you'll get me too confused.

咱们不要离题，否则你会把我弄得很糊涂。

《柯林斯英汉双解大词典》

To reply AD rem is to keep to the subject being discussed.

你的话离我们正在讨论的话题太远。

youdao

Do let's keep to the subject; we're trying to reach an agreement.

务请大家不要离开主题。我们是要达成一项协议的。

youdao

Speaker William Hay intervened, asking Ms McCann to keep to the subject.

BBC: Prison reform programme

But it may be in the administration's interests to keep the subject in the headlines, continuing to suggest that the Republicans will stand in the way of a deal.

CNN: STORY HIGHLIGHTS

Though the software component still needs to be built, the feedback from the forceplate could sense if a patient is about to lose his or her balance and compensate to keep the subject upright.

ENGADGET: vi-RABT improves ankle rehabilitation with virtual reality and robotics