Please read the Hadith in Bukhari that The Holy Prophet (pbuh) made it very much clear to Hazrat Ayesha “O `Aisha! Be sure about your foster brothers, as fostership is only valid if it takes place in the suckling period (before two years of age).
We all know that adult suckling is a big issue in Sunni books of Ahadith, according toHazrat Ayesha’s point of view adult suckling is allowed, even though The Holy Prophet made it very clear to Hzrat Ayesha in above narration.
Please read about adult suckling in Sahih Muslim.
More shocking facts about adult suckling.