Call it sexist all you want. God tells us that the husband is the head of the wife like Christ is the head of the church.
God gave Adam instructions about the Tree of the Knowledge of Good and Evil BEFORE Eve was created. It was clearly then Adam's responsibility to tell Eve. Either he didn't pass the message along correctly, or Eve didn't get it right.
Either way, when Adam heard Eve talking with the serpent, he didn't intervene, nor did he correct her error in what God Himself told Adam.
Furthermore, he WATCHED her eat and then when nothing obvious happened to her, he ate as well.
Scripture also tells us that Eve was deceived. Adam was not. He ate KNOWING.
So, yes, sin entered through Adam and corrupted the whole human race and it is HIS responsibility.
Do you not understand WHY Jesus did not have a sin nature?
So you don’t believe that Eve sinned?