That is Nat Cheating Route (Non Cuckold).
There are several ways to reach this scene (main trigger points are Ethan submissive with or without job). However without job is easier to gather Nat mad at Ethan points.
Step wise ;
From the guide - Follow "Nat Cheat" or "Nat Mad" route.
Or you can choose some variations like let Darrel go with Nat - Express displeasure - looking between Jenna's legs - Curious about Jenna - show shock.
Yes I did look at Darrel. Ask more. Sounds interesting.
Accept Darrel. I wish I could get a job like yours.
Ethan could either follow Nat or Go for interview.
Let Darrel continue.
Sex chat with Darrel.
Jenna seduces Ethan.
Ethan cheating with Jenna doesn't effect this outcome so accept Jenna if you want to see her scenes.
Nat Fucks Darrel in Gym.
Jenna tells Nat to keep it a secret.
Nat becomes cheating wife.
Buy double slit black dress.
If Job = True - Flirt with Riya.
Go to Pub.
Nat lies to Ethan, goes on a date with Darrel.
Ethan found Darrel blogging about cheating hotwife he had fucked. Ethan identifying Jenna and Nat.
Ethan goes to find his wife and confronted her during the act.
Heated argument Nat trusted Darrel and belittling Ethan leaves with Darrel.
Ethan depressed returns home defeated. Next morning Nat returns home after cheating.
Nat belittling Ethan again. Nat dom Ethan sub.
Nat walks past Ethan with a smirk. Next day Nat getting promotion comes home happy then belittling Ethan again.
In evening Nat wearing daring Red dress goes to celebrate with Darrel mocking Ethan again.
Ethan browsing through Darrel's blog finds creampied Nat's pics.
Ethan heart broken goes to drinking. Next morning Sunday smells Nat cooking for herself. Ethan witnessed Nat very happy and humming songs while sipping coffee.
Ethan remembered creampied pics of Nat on Darrel blog. Getting depressed.
Nat ignored Ethan completely as if he's invisible.
Ethan goes out to get his mind straight when he returns..
This scene happens.