Either he's revealing way too much of the next update, or those teasers don't mean much to what's really going to happen.
I believe that nothing sexual will happen in the first part, it's building tension and the finale will happen in the second part
I agree with you, even to me all these revelations at the beginning of production of the next update sound suspicious.
Therefore, in my opinion, the reference to the hot tub is nothing more than a diversion that, as usual, is fed to fans to distract them from where the scene will later take place. I give an example regarding Sam's route: how many of us, based on the teasers released for version 0.150, had assumed that Sam's planned post-concert event scene would take place in his car? Then instead the most interesting part of the scene took place in the hot tub in the Parkers' backyard.
In this case the same thing could happen: it looks like the scene will be set in the hot tub (something we've seen before), then instead it will take place somewhere else in the Parkers' house. Where? If I am not mistaken (based on certain choices made in the previous update) Dylan is supposed to go back to Sophia's room to return the money he borrowed in the afternoon: if he decides to do so this very evening, he might accidentally run into a "moment of strong self-esteem" (aka masturbation) of his mother and...