True, however I doubt it's a mirror to Ian's relationship with Cindy. What makes it such a struggle for Ian is because he's actually friends with Cindy. She's not only Wade's sexy gf, that alone would make his lust easy to deal with. What sells his struggle is the conflict of whether to respect Wade and Cindy's relationship and be a good friend to Wade (ironically dooming their relationship because he can't help them if he stays passive), or be a good friend for Cindy even if it makes him fall for her, making it harder and harder to contain his feelings/lust for her.
I don't feel this level of temptation between Lena and Jeremy, because her sole focus of her attraction seems to be his dick. It's not like they become friendlier and she feels any closer to him as a person, or that Jeremy flirts with her all the time, making her feel good about herself. What's happening is she herself keeps fanning the flames by pursuing her obsession with purposeful morally questionable actions such as spying on Louise, hacking her phone or performing a dare during Ivy's game, then initiating sexting with him, using the opportunity when Jeremy texted to check up on her. Because of all that, it doesn't feel like Lena suffers from some type of inner conflict or has guilty conscience because she constantly chooses to close in on him, willing to throw both her friendship with Louise and her newfound love for Ian under the bus (in fact, she never seems to think about them at the moment) for something as meaningless and animalistic as sex with a big black dick. Like, she could easily substitute Jeremy with Marcel, and it wouldn't be anywhere as toxic as her weird purposefully instigated fixation on Jeremy. If it was GGGB 2, Jeremy would clearly be a Bad Path for Lena, because every action would reward Lena with Bad points. Ian's attraction to Cindy on the other hand is more like Ashley's dilemma with Dave (available as both Bad seduction and Good crush).
TL;DR - Ian's forbidden fruit is harder to resist due to all the complex feelings involved that couldn't be substituted by some other random sexy blonde (like Jessica) and due to all the pressure both from Wade (to help with their relationship and keep an eye on his gf for her) and Cindy (to be a good friend for her) while Lena's forbidden fruit is artificial and mainly motivated by her desire to be an alpha bitch which could be easily satisfied with any other available BBC.
