There are a TON of events in this game so far that would be unlikely to happen in real life, especially involving a woman like Sophia, who is middle aged, well-educated, and seemingly an upstanding citizen. But surprising things happen in life all the time. My wife, who is generally pretty conservative, had her first sexual experience when she was 17 with a man in his 40s. Later in her life, especially now that we have daughters that age, she looks back and sees that experience as unsettling. But she didn't at the time and for many years after.
My reading of Sophia is that she is a very sexual person who let her sexuality get buried by society, her job, her family, etc. Now she is having a mid-life crisis, exacerbated by an inattentive husband. Mid-life crises are common, as is being tempted by and attracted to younger people, especially if they show interest in and attraction back. Sophia is trying to tamp down her sexual feelings, especially knowing they could get her in serious trouble, but (if you make filthy wife choices) she doesn't succeed. And while I'm confident that teachers do not routinely jack off their young students in sex ed classes, how many times do we read or hear about female teachers having sex with their teen/adolescent students?
If you've read Aristotle's views on suspension of disbelief, he makes a distinction between what is possible and what is probable. He advocates that creators should adhere to what is probable to avoid audiences feeling just what you are feeling. Normally I agree with you (and Aristotle). If an event is too improbable in a work of fiction, it feels contrived. But this is a porn game and if there wasn't any sex in it, then AWAM would be an abject failure. And yet, because her actions and character type are totally possible (we have many examples in real life) I find AWAM realistic enough to be wonderfully erotic.