Corruption is only there to be able to do dirty shit (like getting fucked when playing Pool or do more smutty photo shoots).
You have to follow the linear quest line, which has tiered unlocks for sexual interactions with your family members (check the QUESTS button on the left side, if you're stuck).
PS: Let's face it: Porn games - especially HTML ones - are almost always baby dev's first steps.
Very few will start with a bang and most will quickly end with a wimper.
And among the sea of below mediocre crap, this one at least does a lot of things right for a first try:
1. Use the most easy tool to build your game. You want to push content fast, not spend days to learn the ropes for the most fundamental shit.
2. Baseline structure first, story and npcs second.
3. Throw in a whole bunch of random pics/vids first. Make it more coherent later (once you've a rudimentary through-line for your main cast + story).
This list might sound sarcastic, but I really mean it.
I don't want to play the game of someone, who has no idea how to build a game, but wants to tell a grand story with intricate characters and lengthy dialog.
And I don't want 3 carefully selected gifs of each of the 4 main characters and 2 places to visit every two months, because the "dev" wants to carefully build the world from the ground up.