Was Cain a descendant of the serpent, through Eve?

In an article by Ben Heath titled [_Sex Affair in the Garden of Eden_](http://christianovercomers.com/blog/2011/06/03/sex-affair-in-the-garden-of-eden/) , he claims that the sin for which God expelled Adam and Eve from the garden was sexual intercourse with the serpent. Heath goes on to say that Cain and his descendants are literally physical descendants of the serpent, who he interprets as Satan. The doctrine seems to hold a central place in his other teachings. Consider [2 Corinthians 11:2-3:](https://www.biblegateway.com/passage/?search=2+Corinthians+11) >For I feel a divine jealousy for you, since I betrothed you to one husband, to present you as a pure virgin to Christ. 3 But I am afraid that as the serpent deceived Eve by his cunning, your thoughts will be led astray from a sincere and pure devotion to Christ. Heath claims that when Paul uses words translated to _deceived_ and _beguiled_ in this and other verses, a better translation is the word _seduced_, in the sense of tempting to sexual immorality. In addition, [this website](http://www.serpent-seed.com) offers an apology of the doctrine, which it calls the _serpent seed doctrine_, saying: >You see, those who denounce the Serpent seed teaching as heresy not only deny the teachings of our Lord Jesus Christ, but they also miss out on the first prophecy of the entire Bible. According to mainstream Evangelical Protestant denominations like the Southern Baptist Convention, the United Methodist Church, the Assemblies of God, the Presbyterian Church, and the Episcopalian Church, is the serpent seed doctrine a valid interpretation of Genesis 3 and subsequent verses in the New Testament about Eve and the serpent?