If you don't mind a spoiler:
For what I can remember from the novel, basically since Edwin body is a snake beast body, and is unnatural for him to have sex with Leila, because he did it for so long, his sperm kind of forced Leila body to adapt to his, so in this logic Leila became half female snake, so before Edwin he was indeed just a normal guy, but now he have a womb and is able to carry snake eggs, and yes they will have babys
Just found somone who posted the raws and read ahead. Your explanation makes more sense now. Wow, Edwin said he loved leilas pussy so much he actually just got one. Im actually so curious how this manwha will end. Just with them having snake children/ marrying and them just matching eachothers freaks forever. . . .lol
The question is why am I not surprised
Chapter 23 . . . . .is the next kink leila getting pregnant? Because Edwin first has ? For dialog when hes feeling aound inside Leila fisting him and hits what at first I thought was his prostate but then he says "whats this right here?" As if he found somthing unexpectedly and keeps presing into it. Then Leila is saying "Th-there it feels good" then Edwin says back "your really like it there, but why?"(when hes literally jerking it inside of him with his massively large dick and hitting what looks to be a female womb)
I wouldn't be suprised at this point with how the author keeps writing so many kinks in this. Im mostly still reading out of morbid curiosity. But like thats my guess cause that's def not male internal anatomy. To me this is more on par with the shock factor BLs like Dark fall, Mr. A's farm and In the Castle: the Dragon's Erotic Education.