"No One Loves Anyone... For More Than Two Years" is an adaptation of Nelson Rodrigues' work about five couples that live in Brazil in the early 60's, who are seen by the society as conventional people, but whose intimate lives turn out to be morally questionable.
Orozimbo (husband), Elvira (wife), and Eusebio (husband's friend)
Elvira low-key seduces Eusebio, who is in love with her, every time he visits the couple's home. Before Eusebio totally gives in to temptation, he tells Orozimbo that Elvira is cheating on him, but since he can't show any evidence, Orozimbo just gets mad at him. Eventually, Eusebio gets successfully seduced by Elvira and they fuck in a car (56:58).
(Spoiler) Orozimbo, pretending that he's Elvira, tells Eusebio through a note that Elvira would like to meet him. When Eusebio gets to the venue, Orozimbo is there waiting for him and points a gun at him. Orozimbo doesn't want to kill him, he says, because he doesn't want a sad wife. He doesn't want to kill his wife either, because he doesn't want a sad daughter. Rather, he made Eusebio come there to let him see that Elvira is cheating on both of them with another guy. He then guides Eusebio's attention towards a room in the building across the street, and there, Elvira can be seen fucking a guy, someone who is known to both of them (1:14:14).
Elvira doesn't get naked in her two cheating scenes, but she does so in her shower scene with her husband (59:55).
Marlene (wife), Rafael (husband), and Leocadio (husband's best friend)
Marlene rebels against her very jealous husband and seduces Leocadio, his best friend and the only guy he would let near her. She tells Leocadio to come to her house while Rafael is away on a business trip and then receives him while wearing lingerie. Leocadio rejects her because he tells her that he'd rather get shot than betray his best friend.
(Spoiler) Marlene gets pissed because of Leocadio's rejection. She frames him and tells Rafael that he raped her. Rafael shoots Leocadio dead. Poor guy, that's what he gets for being loyal.
Jandira (wife) and Ronaldo (husband)
Ronaldo's new wife Jandira has a very rich family while he is just ordinary and has even quit his job. When Jandira refuses to ask for money from her dad, and instead tells Ronaldo to get a new job, he pimps her to a friend of his: $100 for an hour of sex with Jandira.
Ronaldo brings the guy home (51:20) and introduces him to Jandira, who is confused why the guy is so brazen in hitting on her in front of her husband. During dinner, Ronaldo announces that he will go out to buy something, but he really just goes to another room. The guy starts his move on Jandira, and when she resists, he tells her that he paid her husband to fuck her.
Jandira's resistance wanes off after she knew of the truth. And although crying initially, she then lets the guy fuck her willingly. After that, as the guy is about to leave, she rips off the $100 check in front of the two men. She then tells the guy to come back again and that next time they fuck, it will be free for him. And then she tells her husband that such is not the case for him, that he will have to pay if he wants to fuck his own wife.
Azdrubal (husband), Terezina (wife) and their black maid.
This one is a cheating husband situation, but I'll include it because the black maid is hot. She has a proportionately curvy body and a pretty, seductive smile.
The black maid seduces Azdrubal at 1:02:08. When he comes home, she pretends she doesn't notice. Through singing, she calls his attention towards her quarters, where she is naked and is in the process of putting her maid's clothes on. Azdrubal secretly watches her get dressed. He then comes to her quarters a few scenes later and fucks her on the bed.
The hottest scene for me would be Ronaldo letting his friend fuck his rich wife for $100. The next hottest scene is a toss-up between Azdrubal fucking the black maid and Elvira fucking her husband's best friend.