If established correctly, it's really not all that hard to make a heartfelt romance work within the framework of fucking around. I would say Dreaming of Dana got really close, though I think that it made some sacrifices in trying so hard to be a life sim when it really wasn't one.I'm actually really curious as to how one can prevent themselves from breaking their own in-game law in any heartfelt porn game, since heartfelt means you share a bond, a strong connection with a partner, and not 10 other women you say the exact same thing to. Doubt any woman who has a heart would be eager to share his partner with 9 other woman that you repeat the same "Babe, I love you" to, and not leave your ass. You'll be hearing some heartbreaks for sure to keep inline with that universe's law. :FeelsBadMan:
In my own game I aim to establish a heartfelt romantic bond between Evelyn and both Alison and Erin, as well as sexual relationships with several other characters and a possibility of at least one more romantic connect, but I am not sure how I'd work that one into the narrative. I do this by making Eve honest about who she is to the people around her and making the people around her come to their own decisions about it.
In the next release, as a part of Eve trying to figure out how to connect with Erin, who is sheltered due to her own drama, Eve shares with Alison and Brooke a huge part of her outlook on relationships. She talks about how she used to resent her father after her parents divorce. Her mother had something to do with this of course, bad mouthing him, but the big thing for eve was the revolving door of girlfriends. She thought he was some sort of Gigolo who didn't care about women. But, in the meantime her mother marries and divorces 3 more times. She takes a critical look at her parents and their lives, seeing that her father is happy, his girlfriends are happy, she even notices that some of the ones she thought were little flings a long time ago would come back. Her mother on the other hand is miserable, and in some ways shares that misery with Eve.
This revelation paints Eve's psyche going forward. She's very careful with the L word, and when she does let someone in, she is up front and open about how she is a polyamorous person. It will be up to Alison and Erin then, to decide if they can deal with that or if they need to have her all to themselves. Of course, if you mess things up with them, they'll say no, but since my game isn't using point values, and is instead like an old school adventure game, or the more modern story games like Life is Strange, where you use clues and data gathered throughout the story to better interact with people and get positive outcomes.