I played the final version. The cliffhanger ending of the Chapter 2 and the story until then promised a lot, promised one of the best games, so that's why the disappointment. The last update wasn't on par with the first two chapters, it was very short, rushed and shallow, neither the animations or the writing were on par with those of the first two chapters.
As for the endings, they weren't bad, just the same dark humor of the author that can be noticed in other moments of the game and just as absurd and disconnected from reality as the entire story. As a note, the developer mastered some scenes, like the bj, but the rest aren't on par. Anyway, it's just a twisted erotic fantasy with funny endings in the same style. Many wouldn't consider it funny, few enjoys this trolling style of humor, but I found the Tina ending as funny, only that that ending came way too soon and out of nowhere.
I think the developer should seriously think about another take and restart from the ending of Chapter 2. The premise for this game is too good to let it go to waste. I checked some of his other works and this one has the best premise by far and generally the first two chapters are his best work, so it would be a shame to let it go to waste like this, when he could have the father keep cucking his son and sleep with any new girlfriends his son has. I mean the game could go for a while just doing that and introducing new girls, but the story could go any other way, the possibilities are endless. Maybe with some help the developer can engage in projects with a larger scope. With the skills he already has it's a shame to keep doing these way too short games that end when they are in fact about to get truly interesting.