Choose a character from your favorite fictional universe, male or female, and then create a situation where the character is either cucked, transformed into a bimbo or femboy, or ntr them? Don't know what the proper term for netorare-ing someone is but you get my point. Try to include SPH, BDSM, subdom play, body shaming, and things like that for the characters.

Have them act pathetically, some of them simp for their spouses, others are **** into compliance, etc. Make sure they do different things in different situations. Like you have the mc walk up the door, see the characters having sex and then the choice for the next chapter is they either masturbate at the door or open the door to stop it or get caught and brought inside and the different options are what lead to them becoming a cuck or a femboy or maybe they decide to not look in the door and get ntr'd. These are all guidelines, at the end of the day just be creative and make some good smut for the horny folks