As someone who grew up with hot cousins its a line I wish I could have crossed. But I'm most likely Influenced by the fact that my step-niece and I hit puberty together and did stuff. I don't know what would have happened if her mother and my brother stayed together.
If it's a game like Proud Father or Unnatural Instinct . Probably a lot faster than the MC in most games . I don't think I would get far in most non-vn harems. I don't have the patience to not fuck it up.