One of your co-workers is originally from Saudi Arabia. You like him, and the two of you work well together. However, he stands so close when you speak with him it makes you very uncomfortable. Do you tell him of your discomfort, or do you try to cover it up?
It is important that you point this out to your coworker. This is important for at least two major reasons.
First, if you do not point it out to him, it may harm your personal and working relationship. It is likely that you will start to have nonverbal reactions to him that show that you are not comfortable around him. You might start to shy away from him when he talks to you. He may interpret these nonverbal cues as evidence that you do not like him. This would, of course, harm your relationship. Since he is from a foreign country, it is likely that he will not be offended if you tell him about American ways, particularly if you do so in a sensitive way that makes clear to him that you are not offended by him.
Second, it is important for him to know about American ways if he is to prosper in business and to have good social relations with other Americans. You are not doing him any favors if you let him go on making people uncomfortable due to how close he stands to them. This will marginalize him in business and social situations.
For these reasons, you really ought to tell such a person about how his actions are not typical for the situation he is in.