It is possible that Adam do not understand what Eve said, and do not believe what she said.
According to the Bible:
Adam ate the fruit. He made the decision to follow his wife. Eve said something to him, of course. May be she told him that it was great to become like Gods knowing good and evil. May be Eve already knew that it was GOOD what she did.
Adam was NOT tempted like Eve was (according to the Bible). So, it was decision after some thought process.
God gave two commandments: 1) multiply and replenish the earth and 2)do not eat the fruit of knowledge of good and evil.
God said they will die the same day.
Adam: " So, God gave me this gift, my wife whom I love. God told me to multiply and replenish the earth. God told me that she is bone of my bone and flesh of my flesh. We are ONE FLESH now. Eve already ate the fruit and she will die.
What should I do? (we remember that Adam was NOT tempted as Eve was).
Oh, I know what I will do: I will OBEY the first commandment of God - multiply and replenish the earth even though I have to break the second commandment. From these two commandments of God I choose commandment number one.
Adam has both Eve (at least he thinks he does) and God, why would he want to disobey?
Adam chose to disobey the second commandment so he could obey the first one.
God is so wise. But you don't see this wisdom of God yet. You don't know why God planted this tree in the middle of the garden, why He let Satan to be in the garden to tempt Adam and Eve. You don't know why it was necessary to obey one commandment by breaking the other.
God is so wise.
Satan did not lie. She did not "die".
Serpent did lie. Adam and Eve died the same day AS GOD SAID. Does God lie? No, God doesn't lie.
Only God can promise LIFE, not Satan. Why do you think Satan was called "serpent" by the prophet/s? Because "serpent" is symbol of God of Israel. Satan who was not true God gave the promise that only true God can promise: "you will not die".
Satan didn't look like serpent. He looked like a man when he approached them. But the prophet called him "serpent" because the prophet understood very well that Satan tried to deceive them that he was true God.