User blog comment:B214/Volume 23 discussion blog/@comment-31137559-20170307010853/@comment-31137559-20170308004402

I don't think that's the case. Considering the difficulty of devils having children(not sure how reincarnated devils are subject to that). Him having two children with Rias in 30 years is far-fetched at best. I think it was most likely implying that Issei has a lot more wives that will appear in the future. He still has 11 evil pieces he can use.