The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909), in Parashat Sav (22; listen to audio recording for precise citation), discusses a number of restrictions on one’s conduct with his wife when she is a Nidda. He writes that although Halacha obviously allows a husband and wife to be alone together when the wife is a Nidda, they must refrain from playful behavior; this prohibition serves as a safeguard against sin. It is also forbidden for a husband and wife to directly hand objects to one another during the period of Nidda. If a husband wants to give his keys or a cup to his wife, for example, he may not hand it to her directly. He must instead put it down, and she then picks it up. This applies to both the husband handing objects to the wife, and the wife handing objects to the husband.
The Ben Ish Hai goes so far as to forbid a husband and wife from throwing objects to each other during the period of Nidda. Hacham Ovadia Yosef, however, rules leniently with regard to throwing. He notes that especially if one spouse throws the object up in the air and the other spouse catches it, the one who catches the object receives it by force of gravity, and not directly from the other spouse. Therefore, there is room to allow throwing to one another. Certainly, however, a husband and wife may not directly hand objects to one another when the wife is a Nidda.
The Ben Ish Hai further writes that a husband may not blow a feather or dust off his wife’s garment when she is a Nidda. Although some other authorities rule leniently in this regard, Hacham Ovadia Yosef writes that it is proper to be stringent, and not blow a feather or other items from one’s spouse’s garment during the period of Nidda.
Finally, the Ben Ish Hai writes that a wife should not wave a fan for her husband to cool him off when she is a Nidda, even if they do not touch one another, as this demonstrates affection, which is inappropriate during the time of Nidda.
Summary: When a wife is a Nidda, she and her husband must refrain from acting in a playful manner together and handing objects directly to one another. It is permissible for them to throw objects to one another. They may not blow a feather or dust off each other’s garment, or fan one another.