My rating: 2 of 5 stars
Not averse to the idea of step father / son getting it on, but the idea turned creepy when he thinks of him as his “little boy” / his son and the kid calls him “dad”… The taboo fantasy turned a bit too far fetched with the kids’ confessions though. Also, wtf is up with cheating on your wife with her kid?
Needs a bit of editing, typos, wrong, words, grammar etc. and it might be a good idea, to put the fact that this is basically incest-erotica in the blurp?