There is nothing in the Bible that says that Satan had sex with Adam or with Eve in the Garden of Eden. But this fact has not stopped some people from suggesting the contrary.  One view is that Eve had sexual relations with Satan and then when she had relations with Adam and that somehow Adam sinned in the process. Another view is that both Adam and Eve had sexual relations with Satan. But again, there is nothing in Scripture to suggest that, neither.  Either way, people who hold to this position say that the forbidden fruit was sexual intercourse.

This false doctrine is often called serpent seed and includes the idea that after Eve and Satan had sex, that she bore Cain.  It was Cain who killed his brother Abel (Genesis 4:8).  The descendants of Cain are called Kenites and they wander around the world and are unbelievers.  But, the Bible refutes this idea and tells us that Adam and Eve had relations with each other and as a result, Cain was conceived.

“Now the man had relations with his wife Eve, and she conceived and gave birth to Cain, and she said, ‘I have gotten a man-child with the help of the LORD,'” (Genesis 4:1).

One of the main verses used to support the idea that Eve had sex with Satan is found in Genesis 3, in the King James Version.

“And the LORD God said unto the woman, ‘What is this that thou hast done? And the woman said, The serpent beguiled me, and I did eat,'” (Genesis 3:13, underline added).

In this verse, the focus is on the word “beguiled”.  In Hebrew it is…

 נָשָׁא nâshâʾ, naw-shaw´; a prim. root; to lead astray, i.e. (mentally) to delude, or (morally) to seduce:—beguile, deceive, greatly, utterly.”¹Strong, James. A Concise Dictionary of the Words in the Greek Testament and The Hebrew Bible. Bellingham, WA: Logos Bible Software, 2009.

You may have noticed in the definition that the word “seduce” is included. It is from this nuance that some attempt to support the serpent seed doctrine and teach that Eve had sex with Satan and produced Cain.  But, as was already displayed above, Genesis 4:1 refutes that idea.

So, to conclude, it is false teaching to say that Adam and/or Eve had sexual relations with the devil in the Garden of Eden since the Bible does not say that is what happened.