Board Thread:Manga/@comment-27125793-20190202152111/@comment-34870059-20190312091130

I think he is by now. The Farmer boy is a red herring caused by Isayama to fool the fans. He is a huge GOT fan, and has stated that Game of Thrones might shape his work from now on. And everybody who watches GOT knows there's a lot of secret baby daddy reveals there, so this would be Isayama paying homage to it. Plus, I don't think Eren would want a guy who threw rocks at Historia be the father.

One of Eren's goals until this point is to protect Historia, so having to make a little sacrifice by making her pregnant would lead to their eventual victory. He has a plan, and it would eventually save them all in the end.