Reference for Yevamot 103:9
ועל חתנא דדאיר בבי חמוהי דדאיר אין דחליף לא והא ההוא דחליף אבבא דבי חמוהי ונגדיה רב ששת ההוא מידם הוה דיים מחמתיה
or who allowed a Rabbinical ban upon him to remain for thirty days and did not come to the <i>Beth din</i> to request the removal of that ban; and of a son-in-law who lives in his father-in-law's house. [You say,] only if he lives,<span class="x" onmousemove="('comment',' At his father-in-law's. ');"><sup>24</sup></span> but not if he only passes by? Surely, a man once passed by the door of his father-in-law's house, and R. Shesheth ordered his chastisement! — That man was suspected of immoral relations with his mother-in-law. The Nehardeans stated: Rab ordered the chastisement of none of these<span class="x" onmousemove="('comment',' Cases, enumerated supra. ');"><sup>25</sup></span> except him who betrothed by cohabitation without preliminary negotiation. Others say: Even with preliminary negotiation; because [such a practice is sheer] licentiousness.