You are mostly correct, only sex scenes with another male+female are; Kevin+Teacher and Rick+Emma. Both times Jason gets to watch the scenes from a computer screen or smartphone. Also Jason's presence in the multiple male sex scenes led people to ''cucking too much'' ideas.Correct me if I'm wrong, but not only is there no sexual interaction depicted between one of MC's in-game conquests and another male without MC's permission, there is no such interaction depicted without MC's presence. And to the extent it's possible, it's one beejay scene and one ogling/fondling scene involving Mom and Billy, both of which are repeatable. That's it. (There's an early interaction between Rebecca and Kevin to set her up on MC's path, but that's all)
I do kinda like the idea of MC corrupting Mom so much that he's effectively pimping her out to his school bro. It's an interesting twist (ha!) that's sort of unique to this game.
I agree on the corruption part. It is a nice optional touch from KsT. Though some other games let you do this. Mainly japanese though. From top of my head i can remember Total Seduction also has similar stuff. You can corrupt various characters. Like full corruption on MC's mom results in; she brings co-worker guy to fuck around and you can corrupt some maid and make her fuck other males. Also has various mind control and follow commands for pimping and initiating 3somes.