Genuinely, you need to slow your thoughts here. It’s extremely common for kids to say they’ll marry a family member when they’re that young, since they only see it as staying with that person rather than anything romantic or sexual. The MC having a wet dream when young also has nothing to do with the ML’s actions, and the ML very clearly rejected him when the MC was still a teen. There’s nothing to indicate grooming and saying that it does is really unfair to the author

Seme do slightly child grooming by stating about kissing and marriage to the MC when he is literally a kid...or, uke that wet himself thinking about seme body and dreaming have sxc with him at such a young age...
Style of drawing looks so promising but the background story is such pedo vibe.. And people seems okay with this because the current story show both of them an adult.. one of tactic to twist pedo story to acceptable love story... (눈‸눈)