In De Rerum Natura Book 4 Lucretius writes on the passion of love (Lucr. 4.1058)
I found this interesting excerpt from a JSTOR article on Lucretius:
QuoteYet another factor in Lucretius' treatment of love is concerned in a different way with the concept of romantic love. What Lucretius is attacking is a romantic and obsessive attitude to love which may have existed in life, then and now, and which we certainly find reflected and amplified in literature. In a sense the models of fiction are always more powerful than life, so that Lucretius was right to consider them a special danger; Plato would have agreed with him. Literary models of obsessive love have ranged from Phaedra to Proust's Swann. A particular model that may be useful here is the poet-lover in Catullus' love poems. Since Catullus was contemporary with Lucretius, it is reasonable to assume that he represents attitudes with which Lucretius was familiar. Lucretius' satire on
love gains even more point if it is read as a commentary on the way of life of the Catullan lover. Some critics have claimed that Lucretius is criticizing Catullus' own words and the way of life of his circle of friends; we may at least take the Catullan lover as an example of the type Lucretius has in mind, a type that existed in Latin literature, especially in the sub-category exclusus amator, as early as Plautus and Terence.2' This type
exemplifies a rival kind of withdrawal from everyday Roman life and perhaps even an insidious popularized form of Epicureanism which Lucretius may well have been anxious to combat.
"Lucretius and Love" - Aya Betensky
The Classical World, Vol. 73, No. 5 (Feb., 1980), pp. 291-299 (9 pages)
https://www.jstor.org/stable/4349198
QuoteIt was probably in Rome that Catullus fell deeply in love with the "Lesbia" of his poems, who is usually identified with Clodia Metelli, a sophisticated woman from the aristocratic house of patrician family Claudii Pulchri, sister of the infamous Publius Clodius Pulcher, and wife to proconsul Quintus Caecilius Metellus Celer. In his poems Catullus describes several stages of their relationship: initial euphoria, doubts, separation, and his wrenching feelings of loss. Clodia had several other partners; "From the poems one can adduce no fewer than five lovers in addition to Catullus: Egnatius (poem 37), Gellius (poem 91), Quintius (poem 82), Rufus (poem 77), and Lesbius (poem 79)."
Regarding marriage and adultery in ancient Rome I also read on Wikipedia:
QuoteDuring the Republican era, marriage, divorce and adultery were matters dealt with by the families concerned. Falling marriage and birth rates in the Later Republic and early Empire led to state intervention. Adultery was made a crime, for which citizen-women could be punished by divorce, fines and demotion in social status; men's sexual activity was adultery only if committed with a married citizen-woman. Families were also offered financial incentives to have as many children as possible. Both interventions had minimal effect.
And so we need to take into consideration the historical context of the time in which Lucretius wrote De Rerum Natura.