Artificial Academy 2 has a module on one of its mods that allows netorase/cuckold play with the lover of the current protagonist, you just need to have i believe both of the bull and the lover on a good relationship and in a horny state, then you must select "try to get along with" or "get along with everybody" and they will try to seduce either the selected partner or someone they prefer, if they succeed they will either inform you so you can watch them have sex or they will just start going at it in a discreet place without telling you so everything feels more secretive. Anyway if they decide to ask you to watch then you will follow them to a discreet place to see the whole thing, it's like a regular sex scene but with the bull, and it honestly takes too much time for my taste, but hey some may prefer it that way. When it ends they just get out and the lover always asks you to have sex with them, i guess it's because they want to you "reclaim" them after having tons of sex with the bull, and that's pretty much it.
Honestly this is great for role-playing and because all the freedom the game gives you, you can create a bunch of situations. If you want you can make your lover sleep with everybody in class, or just a few, or maybe lesbian only, you can make them fuck gigachad or the weakest male on the class, even the ugly and bald teacher. The best thing is that this is pure netorase, and you relationship will remain the same regardless of what you do, unless you decide to give your lover the cheating trait and low virtue, in which case i believe they will start sleeping left and right as soon as you give them the green light.
The only thing i would've wished is honestly more dept and flavor, but sadly there is so much you can ask for a single trait from a bunch of other ones, still i would 100% recommend if you like netorase.