Good Jessica will shoot anyone down. She is not a cheater. Ashley is the person who brought her some stability during a time of chaos, and she will be loyal to the end.She went for Jeremy because Ian didn't show any interest towards her(player choice). If you go for vanilla Alison path she's as faithful as the other girls on vanilla path. Why would she wait for a man who shows no interest towards her? Also she's still recovering from her breakup, people look for validation from others when they go through this phase, hence she was very receptive towards simple flirting.
Though I agree, her behaviour is pretty shitty when she wants Ian's attention, non Alison path is tryharding slutty Alison which is pitiful.
Jeremy's flirting game is so trash that he got shit on by both version of Jessica . So, you can understand how needy was Alison because she liked his flirting.
Bad Jessica is a good woman that has made a lot of bad decisions and she was corrupted by modernity, and the partygirl lifestyle. She knows that she has "Hit the wall" so to say, and wants to be good. I think she has been hurt a lot by acting like a slut, and doing drugs. She wants to be a good girl / trad wife deep down. However, her emotional damage may be beyond repair at this point. She has been pumped and dumped one too many times. She got into porn. She started to realize that her body was all she was good for... Unlike other "Happy Variants" of Jessica. Such as when she ends up with Dave, they both like that drawing stuff and get along great. She may have some "Bad Boyfriend" at this point as well, but it's unclear who. She did have a busted lip, and she did need a place to stay. So, she may be shacking up with some abusive dude.
Honestly, Jessica could have her own entire game with her as the protagonist. A sort of "Bad girl gone good." Try to be more innocent, and pure, but she has already seen the evils of this world.
Is it too late to save Jessica?