Exactly how steamy is this story?
PG-13
Sex shows up only briefly in the Manifesto, but it makes kind of a splash when it does.
Marx writes that the whole bourgeoisie screams in chorus against the supposed communist view on what he calls the community of women (Section2.45). That would be quite a lot of people screaming simultaneously. Anyway, by community of women Marx means, according to his explanation of the term in Economic and Philosophic Manuscripts of 1844, a system in which women are free prostitutes to the entire community.
Okay, that's not actually what he meant, but it's what his opponents falsely accused communists of promoting. In the Manifesto, Karl was mostly interested in criticizing bourgeois marriage as hypocritical, since the bourgeoisie treated their wives as private property and were busy seducing each other's wives (Section2.48-50). Marx doesn't much indicate what he favored instead.
So, yeah, if talk about prostitution makes you feel awkward, you're gonna feel a little awkward with this one, though it's not like old Karl ever actually gets down to the nitty-gritty details.