Who is best served by gender inequality? Since stereotypical families are the cheapest form of producing new workers for the workforce, capitalists earn a surplus from heteronormative families for whom the mother raises children at no extra cost.
Engels' ideas on the role of property in the creation of the modern family questions monogamous relationships and the freedom to enter into (or refuse) such relationships. Bourgeois law dictates the rules for relationships and inheritances. As such, two partners, even when their marriage is not arranged, will always have the preservation of inheritance in mind and as such will never be entirely free to choose their partner. Engels argues that a relationship based on property rights and forced monogamy will only lead to the proliferation of immorality and prostitution.
The only class, according to Engels, which is free from these restraints of property, and as a result from the danger of moral decay, is the proletariat, as they lack the monetary means that are the basis of (as well as threat to) the bourgeois marriage. Monogamy is therefore guaranteed by the fact that theirs is a voluntary sex-love relationship.
Capitalist consumerism shapes contemporary sexuality: the perception of the social relationships involved in production, not as relationships among people, but as economic relationships among the money and commodities exchanged in market trade. Therefore, the market exchange of commodities masks the true economic character of the human relations of production, between the worker and the capitalist.