That's pretty much the premise of this story. I won't go into too much detail but the sons drive towards his mother comes from purely oedipal and carnal desires. Sure at first both of them are completely oblivious to what they truly want deep down, and it's a rough psychological challenge to discover and accept their inner impulses. But the son doesn't even consider resorting to trickery or corruption, he just needs to express his natural love for her mother until she recognizes how pure and precious it is, even though it's behind a huge concrete wall of taboo.
That sounds like a viable premise. And just to expand on an example:
The boy is learning and figuring things out - and he's attracted to his mother. Since he's innocent (i am guessing) he doesn't realize that some of what he's throwing out is a clear sign of attraction to his mother (who is smart enough to pick up on it - as she's a grown woman). She can be flattered by the attention, turn it down, get angry with him, or maybe just assume its a harmless phase and tease him about it from time to time (especially if she generally is an attention seeker). The teasing doesn't go missed by the player, so the story can progress to the point where eventually one or both of them decides its no longer taboo or lets themselves drift into the grey area.
At that point, maybe things that were innocent in the past - backrubs, accidental nudity - are no longer innocent, but deliberate acts of breaking the other character's taboo.
A game could go back and forth in this grey area for a while - until something disrupts it. Maybe the mom sees another lady making a pass at her son (or more). Maybe the mom makes an extremely poor lapse in judgement and gets caught spying on him.
Anyway, nice to hear you have some good ideas. Hopefully you can get your developers rolling with some new updates.