According to Osho, a fixation on asking about sex with close relatives betrays a hidden personal involvement or conflict, not sincere inquiry. He withholds public answers to spare the questioner and their family from shame. He adds that incest taboos are grounded in biology: genetic closeness dulls vitality, whereas greater distance fosters healthier, more intelligent offspring.
If someone keeps asking about sex with family, it likely shows their own issue; Osho stayed quiet to protect them, and says it’s unhealthy for children for scientific—not moral—reasons.