What would rava and abaye think (according to rav) in YEHUDAH, as we learned formerly in yevamoth (and ktuvoth) that the couple was together before marriage? Rav has to say that the child is from him, isnt it?
In Yehuda, the Minhag was to allow the couple Yichud, in order that they be farmiliar with one another. However, even in Yehudah the couple could not live together as man and wife without Chupah. Therefore, the entire discussion of Rava and Abaye applies even in Yehudah.
DOV ZUPNIK