Brachot 24 - Saying Shema in the presence of nakedness
If two people are sleeping in one bed, and their buttocks are touching, can each turn his face away from the other and recite Shema? Some say that it is permitted, and even when the other person is his wife. Others say that, just the opposite, only with his wife it is permitted, because he and his wife are considered as one flesh, but with others it would not be allowed.
However, one should not say the Shema while looking at any part of a woman's body that is normally covered, and now happens to be uncovered. When does this apply? It goes without saying that one cannot enjoy a woman's beauty if she is not his wife, and looking at any part of her for his gratification is forbidden. This applies, however, to saying Shema while looking at his wife, looking at her hair, or listening to her singing.
Rabbi Chanina said, "I saw that during his Standing prayer Rabbi Yehudah the Prince belched, yawned, sneezed, and spat upon the ground." How was he allowed to do this? - Belching and yawning are indeed allowed if done involuntarily, provided that when yawning one covers his mouth. Sneezing - if it is a euphemism for passing wind, then indeed it is not allowed, but sneezing with one's nose is actually a good sign: just as he got relief in this world, so he will get relief in the next one. Spitting is allowed if it bothers him and he does not have napkin, and even then, he should spit to the back of himself, and pause after it.
Art: Sir Anthony Van Dyck - Portrait of Mary Ruthven, wife of the artist