R. Yochanan citing R. Banayah: One partner can object to any use that the other partner makes of the courtyard except for (the women) laundering, because of the honor of Jewish women (so that they will not need to launder elsewhere thereby exposing their lower legs to the public.)

R. Matanyah: This refers to places where the women do the laundry, but if the men launder, the partner can even object to laundering.

When we say that he may not object to women laundering in the courtyard, it does not apply to his own personal area of 4 amos.

When we say that one partner may object to the other partner's use of the courtyard, it does not apply to the personal 4 amos of the other partner.

If the courtyard was sloped, if one was pouring (thereby producing dirty water) in his part of the courtyard, the other partner can object and say, "You are pouring it in your half but it is flowing into mine!''