C373
Lu Chen didn't hide anything from Leng Meng. The only thing he didn't tell Leng Meng was the fact that the Sect Leader had died in the end, which was recorded in the ancient book.
What happened a thousand years ago, even if Elder Sister Meng knew that the Red Lotus was stolen by her ancestors, it would not affect her in any way. However, if she knew that the sect was surnamed Leng