Sasuke and Sakura made a non-faulty mistake and their eternal punishment is a baby which they didn't create or wanted but the baby is theirs. Now how is that possible?
Sasuke did the only thing he thought of after he came back, claim Sakura is what he did but how? Impregnating her of course. Seriously, not what you perverts are thinking, I don't write those stuff. RATED: T! Just so you know.