For Stephen Dedalus, a character on the periphery of the Bloom marriage, sex is at first an avenue of self-exploration; in Portrait of the Artist as a Young Man, the precursor to Ulysses, Stephen seeks a prostitute as a means to an end, and comes away from the experience haunted by his actions. There are not very many examples of a sexualized Stephen in Ulysses, perhaps in part due to Stephen’s sexual past (which his companions Dixon and Lenehan tease him about in the “Oxen of the Sun” chapter; 321. 337 - 340), which is something that has caused him to be cautious of his sexual desires. It is also possible that Stephen’s monumental intellectualism has been developed by him in order to aid him in rationalizing away the sexual desires that may confuse or upset him.
In the depictions of sex in Ulysses, there is a distinct difference between procreative sex and sex for pleasure. Thematically, sex for pleasure is characterized by adultery (Molly and Boylan), the use of prostitutes (both literally and figuratively), and as a form of sexual release (as in the Nausicaa chapter). Sex for pleasure, or hedonistic sex, is sex that carries a negative connotation with it, by way of its damaging effects—the strain on a marriage, or, from Bloom’s point of view, a lack of cleanliness.