>>938616144 (OP)
Not as good as parent child, but still based. I'm biased though. My sibs are objectively attractive, but I was never that close to them so it's hard to imagine. On the other hand, I was a little pervert growing up before I even knew what that meant. I would've loved if an adult family member stepped forward and got physical with me. Looking back, I wonder if it was obvious I was practically begging to be molested and the adults just ignored me.
Either way. When done with care parent/child>bro/sis