Responsa על יבמות 48:21

Q. A, of priestly lineage, saw his wife L go to a secluded place with a certain young man. They stayed there only for a short time, for L's mother walked toward them with a lighted candle. On another occasion, while lying in bed late at night, A heard, on the other side of the wall, the heavy breathing of his wife and the young man as they were arduously embracing each other, which to him was clearly indicative of consummated sexual intercourse. The same incident was repeated on another night. On these occasions L was late coming to bed. Next morning, however, when A rebuked L for her lewd conduct, she protested vigorously. Nevertheless A was convinced that his wife commited adultery and was, therefore, forbidden to him. A had always loved and catered to L, but she had never returned that love, and had never submitted to him willingly.
Rabbi Hezekiah b. Jacob, to whom the question was first submitted, ruled that L be forbidden to A.
A. One judge is not at liberty to permit what another has prohibited. Were I present at the time when Rabbi Hezekiah received the query, I would have argued the case with him. A woman is not forbidden to her husband unless either: a) the husband is jealous of a certain man, and warns her against private meetings with this man, and the wife disregards this warning in the presence of witnesses; or b) they actually be found in a position indicative of fornication. But, heavy breathing itself is no indication that illicit sexual intercourse took place. Therefore, I shall wait till Rabbi Hezekiah recuperates from his illness, whereupon I shall discuss this matter with him.
SOURCES: Pr. 98; Am II, 63; Rashba I 832–3; Tesh. Maim. to Ishut, 8; Hag. Mord. Kidd. 549. Cf. Asher, Responsa 32, 11; Weil, Responsa 8; ibid. 88; Israel Bruno, Responsa 5; ibid. 7; Isserlein, Pesakim 222.