isnt that how Jeremy character made for? he is free spirited man and doesnt really care about serious relationship, he just wanna having fun and everything is based on your playstyle, if you choose Ian not chasing after Alison, Emma or Lena and only chasing holly, you cant blamed Jeremy if he choose to chase after Alison, Emma or Lena, because you are the one who doesnt let Ian chase after them and that girls its not Ian property, everyone had a chance with them. And jeremy as always, wanna had fun with them and them girls also like it when they had fun with jeremy not some rape type of shit.Difference is that you can choose to be a good guy or a dick with Ian. You don’t have to pursue Cindy unless you want to, where Jeremy will go after nearly anything with a pulse.
And about Jeremy cheating with Lena even though Lena and Ian kinda became couple and Jeremy knows it, you can always stop it from happening by not allowing Lena to participate the truth or dare and not having sex with jeremy in the morning, like how you can prevent Ian chasing after Cindy like you just said, thats why this game had two protagonist you can control both of them.