Is it permissible for a male cousin to marry his female cousin if his sister was breastfed by the mother of the male cousin many times, to the point of satiety?

The question is unclear, and the answer varies depending on the nursing mother:

If the nursing mother is your maternal aunt: Your sister becomes a daughter to your maternal aunt and is forbidden to her sons. You have no relation to this nursing, and your maternal aunt's son is permitted to marry your daughter. If the nursing mother is your mother or your father's wife (and your sister is only your paternal sister): You become a sister to your maternal aunt's son, and he is not permitted to marry your daughter.