Well, now that I think about it, most of the time Sophia does NOT stop him and lets Dylan continue (e.g. when she did not resist when he kissed her and grabbed her butt on the dance floor, when she let him suck on her nipples, when she let him put her hand back on his cock, etc.), she only stops him when he is about to do something related to penetrative sex, which is almost non-existent in the game so far.
But I'd like to know how Sophia will behave now that Dylan has confirmed to her that he sees her as a woman and is not ashamed of it. So the excuse of doing it for "educational purposes" is already out the window.
And also, how long will it take Sophia to break down the taboo barrier, because that's what's holding her back the most from taking a step forward with him, since she really feels attracted to him at times beyond a mother-son relationship (she even has sexual feelings for him).
Although this will most likely not happen in the near future...
PS: Screw you Sam!