Seem to like it
In addition to its anality, another peculiar feature of Bloom's sexuality is a tendency to masochistic self-abasement. These fantasies will not become fully manifest until they are enacted in Circe, most decisively in actions inspired by the writer who lent his name to the phenomenon, Leopold von Sacher Masoch. But their presence is announced early in Calypso when Bloom thinks about his cat, "Cruel. Her nature. Curious mice never squeal. Seem to like it."
It can hardly be an accident of Joyce's writing that the cat is female and that her vocalizations ("Mkgnao!," "Mrkgnao!," "Mrkrgnao!") resemble those of the half-conscious Mrs. Bloom ("Mn."). Bloom's reflection on his cat's cruelty, and his uncharacteristically unrealistic thought that her victims too may be deriving pleasure from her claws, suggest that he is constructing Molly in fantasy (though perhaps unconsciously) as a dominatrix and himself as a passive but willing sub. Many details of the novel support this impression, leading up to the extravagant hallucinatory events in Circe.
As Calypso continues, more of Bloom's thoughts and actions suggest that he does derive a certain pleasure from submission. As he waits in the butchershop, eyeing the servant girl in front of him, he remembers in strongly suggestive terms the way he has seen her beat a rug in the garden: "Strong pair of arms. Whacking a carpet on the clothesline. She does whack it, by George. The way her crooked skirt swings at each whack." Two paragraphs later, the pleasure he takes in watching her vigorous beating is juxtaposed against his passive sense of subjection: "He held the page aslant patiently, bending his senses and his will, his soft subject gaze at rest. The crooked skirt swinging, whack by whack by whack." Several paragraphs later still, his voyeuristic leering in the butchershop, and the girl's disinterest, give him further occasion to become aroused by abasement: "they never understand. . . . The sting of disregard glowed to weak pleasure within his breast."
Bloom's tendency to become a servant in his wife's presence—bustling about to anticipate her desires and execute her bossy orders, identifying with Mozart's Leporello—is another aspect of this submissiveness. So too is the helplessness that he feels with respect to her adultery. In the face of both Molly's infidelity and Milly's sexual maturation, he experiences physical sensations that sound sickly but also vaguely erotic: "A soft qualm, regret, flowed down his backbone, increasing. Will happen, yes. Prevent. Useless: can't move. Girl's sweet light lips. Will happen too. He felt the flowing qualm spread over him. Useless to move now. Lips kissed, kissing, kissed. Full gluey woman's lips."
The letter in Lotus Eaters shows that Martha Clifford is well aware of Bloom's submissive tendencies, and willing to play along: "I do wish I could punish you for that. . . . Please write me a long letter and tell me more. Remember if you do not I will punish you. So now you know what I will do to you, you naughty boy, if you do not write." When Bloom writes back to Martha in Sirens, he thinks again about the servant girl beating the carpet: "How will you pun? You punish me? Crooked skirt swinging, whack by. Tell me I want to. Know."