The Infinite Mage - Vol. 1 Ch. 2

[MangaDex]

 

[minsam]

if kid turns out to be a lost noble child then i flip the f out.

 

[Gletscher]

if kid turns out to be a lost noble child then i flip the f out.

Well, we know for sure he isn't the biological son of his dad though, so that's always a possibility.