Jenny's storyline takes a good chunk of your playthrough to complete and is directly linked to your ability to upgrade the Dexterity Stat so you will want to keep on top of this relationship.
WARNING: SPOILERS AND EXPLICIT CONTENT AHEAD
This game is explicit and features sexual acts and content for the entire campaign. This wiki may show that content as well as reveal spoilers for the story. Don't say we didn't warn you.
This game is explicit and features sexual acts and content for the entire campaign. This wiki may show that content as well as reveal spoilers for the story. Don't say we didn't warn you.
You'll first meet Jenny on Day 1 when you bump into her in the corridor when leaving for School. She doesn't seem to like you very much.
Part 1
Head to the gym and talk to the old man by the punching bag - he will offer you Muay Thai lessons in exchange for some panties.
Go back to your house and go to Jenny's room which is between yours and the bathroom and start snooping around. 
If you open her bedside draws you can see some panties but she will catch you before you can take them. 
After you explain she will offer to sell you panties for $100 and once you purchase them you will be able to train at the gym for the first couple of levels of dexterity. During your training one day in the corridor, you should be able to sneak a look at Jenny while she's showering. She will notice and kick you out.
You will need to complete training every day until the master turns you away and also work to advance the storyline with Jenny's mum Debbie before you can continue with Jenny's relationship.
Part 2
Once you have advanced Debbie's storyline to the point where you watch her masturbate on her bed and Jenny catches you, you'll be able to talk to Jenny and choose the 'Debbie needs you' dialogue option.
This lets you sneak into Jenny's room while she's gone to read her diary and get the password BAD MONSTER to access her PC. If you try to use her PC during this scene she will catch you so come back later. 
By this point you should have completed as much Dexterity training as you can before the master sends you off to get more panties so go and talk to Debbie once more about purchasing her underwear. Debbie will want a sex toy as payment this time so you'll need to head to the Mall and purchase an Electro Clit from Pink which will cost $100 and is up the escalator.
Exchange the toy for panties and bring it back to the gym to continue training your dexterity every day until you can't raise it any higher. At night sneak into her room again to log onto her computer and connect her webcam to your computer so you can use your PC to watch her cam shows. You can also grab the login details for her porn account from her email for later.
Sneak into her room again at night and choose her bed to get in and cuddle her. She'll wake up and kick you out
Go into the corridor and if someone is in the shower check to see if it's Jenny and choose to peep. - You may need to do this on two separate occasions to trigger the next event. One morening you should wake up wondering what Jenny is doing, so check your PC and select webcam to see if she's putting on a cam show and you'll see her using the toy you purchased.
Once the show is over use the telescope in your room and Jenny will interrupt you. 
Part 3
After you've slept, head downstairs and talk to Debbie in the kitchen who will have made you some breakfast. Go into the dining room to your left and select the table to eat it and you'll have a conversation with Jenny where she wants you to lend her some money in exchange for some deal. Sleep again.
You'll need $500 to give her so when you have that go to Jenny's room when she's there and agree to the deal. Choose to suck on her boobs despite her saying you can only touch with one hand and then select stop. She'll get angry and kick you out of the room again. 
You may need to also sneak into her room at night and get into her bed again to trigger the next event. You should be able to see her showering again soon in the corridor so check during the day before you head out to do anything else. You'll have the option to go inside, then when she confronts you choose the 'need help' option.
Jenny will demand you beg to see her and you should comply but at this point, she'll decide you don't deserve it and kick you out again.
Doing this should trigger another cutscene in the hallway the next day where Jenny confronts you about going on her computer.
At night you can go to the living room to see Jenny watching porn on the television. Choose to keep watching and this will give you the bright idea to also watch porn on the tv using her account. 
You can do this by coming to the living room at night, selecting the Pink Channel, and using the login details found on her email on her PC which are ID: L6BV12R Password: 12345. 
After doing this once you'll wake up the next day wondering if you can go train at the gym again. Part 4
Go talk to the Master at the gym again and he'll once more ask for different kinds of panties.
Return to Jenny and relay this request and she will ask for an Ultra Vibrator which is $200 from the Pink store in the mall.
Buy it and return to exchange it for panties and the panties in turn for more Muay Thai training - resume levelling your dexterity up every day. At night watch the pink channel again on the TV to trigger a scene where Debbie hears the television but you hide before she can catch you.
To trigger the next webcam event you may have to talk to Jenny, watch her shower again, and sneak into her bed at night. Eventually, you'll wake up wondering what Jenny is doing again, so check webcam and you can watch Jenny using the new toy then go on your telescope again like before to trigger another scene where she catches you only this time she'll want to join in.
Part 5
Sleep again and go out into the corridor for a scene where Jenny gets mad at you for being with Debbie because she needs you to buy her more toys.
To continue go to bed again and the next morning walk past the bathroom. You'll be able to progress with her shower dialogue after begging but soon after she'll kick you out. That night choose to watch the TV again to trigger a scene where Jenny catches you and accuses you of stealing her login details before giving you a footjob. Choose to cum to end the scene.
Head to her room again at night to sneak in her bed and you can progress to the 'Rub Pussy' option before being kicked out again. When you wake up the next day you'll once again wonder if training at the gym can resume.
The Muay Thai Master will want more panties so go talk to him before returning and explaining the situation to Jenny. This time she will send you off for the Dual Sybian sex toy which will set you back $500.
Buy the toy and bring it back to get your panties to continue levelling up your dexterity. Soon you should be prompted to check your PC for Jenny's webcam to see her using the new toy and then again look at your telescope to trigger a scene where she walks in on you again.
Part 6
By now you should be fully levelled up in dexterity so go to her room and bed again at night and you'll be able to progress to the 'put it inside' option before she kicks you out of her room again.
The next day in the corridor you'll hear voices coming from her room and if you look in you will see Jenny talking to her viewers about what they'd like to see next via her laptop
After another day has passed you can trigger a cutscene in the hallway where she will ask you to get her some handcuffs and a cheerleaders outfit to be rewarded. 
You can purchase the handcuffs from Pink at the Mall for $50. 
To get the cheerleaders outfit you'll need to go to your garage and grab the stool from on top of the shelf and then to the main downstairs room of your house to get the key off the key rack on the wall. 
Then go back upstairs and choose the entrance to the attic where you'll find her old cheerleader outfit hanging up. 
Go to sleep again and bring the items to her in her room the next day. She will handcuff you to the bed to sex with her on camera for her viewers. 
If you have enough Strength you'll be able to break free from the handcuffs and cum inside of her - if not you won't be able to do this and can't progress any further until you get stronger. Part 7
After you've managed to cum inside Jenny there isn't really any story progression left but you do still have a few things you can choose to do with her.
Now you'll be able to go into her bed at night and progress to the 'Rabbit Fuck' option and 'cum inside' again.
You can also progress further with the shower options to 'cum inside' as long as you can pass the strength check.
Talking to Jenny will also bring up a bunch of new options.
If you choose 'Watch the Neighbours' you and Jenny will go into your room and look through your telescope where you see Erik going down on Mrs Johnson. Jenny will demand you do the same for her which results in a scene on your bed. Choosing 'Watch TV' will allow you to reenact the footjob scene the following night but this time you can also have sex with her on the couch.
Ask her if she needs any more toys and she'll tell you about the Bad Monster toy she wants from Pink which costs $500. If you get it for her you can watch her use it as well as all the other toys on her webcam from your computer.
You can also choose to do more Cam Shows which is just the same scene as before and you can talk to her or tell her you love her but she will react angrily to both of these things and they don't change the story.