Is it permissible for a brother by fosterage to the younger brother to marry the sister of the elder brother?

If a person suckles from the mother of two siblings, he becomes a foster brother to both of them, because the milk is one. Fosterage prohibits what lineage prohibits. The suckled person becomes a child to the woman and to the owner of the milk, and this prohibition applies solely to the suckled person, not to his siblings. Therefore, there is no objection to the fosterling's brother proposing to the daughter of either of the two siblings, because the prohibitory relationship is established only for the fosterling himself. The suckling must consist of five full feedings to establish the prohibition.