So far as parents allowing kids to sleep with strange adults: I don't believe nearly anyone here would. But there are those who would, and do.
I'm going to try to expand on this a bit, because I really feel like it's a major point that seems to go right over the heads of many.
I think *most* of the people that find their way to this message board grew up in fairly stereotypical families: Mom, Dad, kids. Maybe grandparents and extended visited, maybe the spare room had a permanent resident aunt or other relative. But for the most part, folks here grew up in single family homes or single family apartments, that actually housed the members of a single family.
But for many people in the USA, that is a pipe dream. Two miles up the road from me there's an apartment complex that's mostly filled with temporary farm workers. They often live with three or even four families all crammed into a single two bedroom apartment. Multiple adults, multiple children, even multiple pets, all eating, living and sleeping in fairly haphazard arrangements. It's not unusual. It's not weird. It's LIFE for them. And yet, any kind of weird sexual relations between the peoples in these circumstances is just that: weird.
Many of us are descended from pioneer families who lived in tiny cabins, and all slept together in one giant bed. It wasn't strange or a disaster waiting to happen. It was just LIFE.
I don't know much about MJ's early life, or the lives of his parents. But I wouldn't be surprised if his parents lived in very small houses, with extended family. I wouldn't be surprised if they told stories of "those good ol' days" to their children, and MJ built some fantasy in his head that those kinds of sleeping arrangements were happier, healthier, and a vital part of his dream childhood.
The people he was associating with were mostly wealthier, to be sure. Jordan Chandler's father was a famous dentist. But as most or all were black, I'd guess most of them had the same communal living as part of their heritage.
When we're considering the actions of any person, we need to step back, take a longer look, and see just what kind of tail is on the damn kite before we jump to the conclusion they're too weird for words. Because what might seem alien and weird to you and I, might just be perfectly normal for THEM.