A short guide for this buggy game, there's a lot of things that can freeze and small glitches that can make you stuck so save often.
Arousal is your main progression with your Aunt. When it reaches to 100%, you will automatically go to the scene and gain 1 heart (Max 4 hearts) as well as unlock some things.
Ways to increase your arousal (most optimal path)
0 heart - Get the strong aphrodisiac from the guy you met outside, put it in the coffee machine in Jay's kitchen. You will gain 50% arousal. After that, you can hug your aunt for 4 points Arousal, but this is very time-consuming to do it everyday. So at midday-night, go around the map and find the shiny looking objects. You will find Golden coins which you can sell it to the guy you met earlier for cash. He's at the dumpster near the library. What you really want to look for is the "
Damiana Petal" that spawns randomly on the map outside from the house and near to the bench at home. These Petals can be added into the Coffee Machine for random Arousal points (4%-20%) Save first before you add the Damiana Petal!!! You want to maximize your Arousal for 15+. Anything lower, you can quit and reload the save and try again for a better result. It's RNG.
Keep doing this until you reach to 100% Arousal and then enjoy the scene.
1 Heart - Hug is increase to 7 Arousal points. No follow and no undress at 1 Heart. You will keep farming for Damiana Petals daily and adding it to the Coffee Machine. Remember to save for optimal percentage numbers. Reach to 100% and unlock the next scene. Enjoy
2 Hearts - Your Aunt can finally follow you by "Order". No undress at 2 Hearts. Unlocks "Cafe" Now this is the easy part, you no longer have to farm the petals. You can start doing a few sex scenes.(Have your Aunt follow you and you will see "Hearts Icon lying around in specific spots) So far, "Handjob" at Bench in home (Go down the hallway and past Jay's bedroom) and "Clean with mouth" in Bathhouse/Sauna. Do not pick "Clean with Pussy". That will break the game and freeze.
But the best farming method is trying to fuck in Jay's bedroom. You will fail, but you will gain 12 Arousal points and did I mention, It's repeatable? So you will keep doing this until you reach 100% Arousal. Enjoy next scene.
3 Hearts - You can finally undress Aunt. But only underwear/lingerie. Booo. Nude is only unlocked in 4 Hearts. But now you can fuck your Aunt for Arousal points. Also when you hug your Aunt, you can fuck her for more Arousal points. Also there is a key to Jay's bedroom in the nightstand next to Jay's bed. So far, there is no scene/content when you try to engage with her at night. Extra boooo. Either way, have your pick(Jay's Bedroom, Against the wall in Old Block park, and Dumpster fuck behind BathHouse/Sauna, there's a narrow space next to Vending Machine) and keep raising your Arousal points to 100% to reach the next scene. Enjoy!
4 Hearts - You can now finally undress Aunt nude. Wooo. At this point, there's not much going on except fucking your Aunt nude now. "Spa" is unlocked after you reach 4 hearts. Also there is a sexy Vendor that comes occasionally in the Old Block next to Spa. RNG. You can enter the "Library" and "Church" and see the intro scenes, but that's it. There's no further content until next update. Also couldn't find all the Golden Coins and there is some items that could unlock some scenes, but I haven't tried it. You have to farm money by helping out your Aunt and that's a long time.
Hope this guide was helpful to you. Remember to play with one hand, fellas!