The Dev should have given us an option to avoid him completely if we wished, but no, our bone idle lying lazy developer didn't give us the choice in the first place. Just like Azel kidnapped the MC after his dad died, because she knew full well she would never have stood a chance of getting adoptive custody of him. Single people never get adoptive custody of a child. Aside from the 12 month wait to get onto the adoption list, because of all the background checks..at this point they would be denied because she is single, end of her chance to legally adopt him, this is how the law works and how most social services in most English speaking countries work too.
Which legally means if he has sex with Azel or vice versa it's not incest, it doesn't remotely matter what the brainwashed MC thinks, (at some point has the MC is growing up it's clear Azel lied to him about her adopting him, because as mentioned she did not, it also begs the question why did the police not turn up and the social services getting involved? did she change the MC surname as to throw the police and social services off or something similar?) The stupid Dev doesn't get into the exposition of what the fcuk happened to the MC after Azel took him, kidnapped him, which is a huge glaring plothole at the start and makes no sense why two people who clearly are enamored with each other cant have sex and the false claim she adopted him!) because at the end of the day she was never his mommy either adoptive, fostered or biologically. Get her in the harem, both the MC and her make a cute couple, they both made concious decisions when they played tonsil hockey with each other. Either one of them could have said no, and I doubt the MC would turn her down for some after hours extra curricular activities. Now with his real sister and real mom, of course not, he made it clear he was being shit-house when he said he didn't want incest in his game despite the fact he claimed he thought about it, he was just too scared of patreon banning him..which is no excuse, patches are a game's best friend.