Gendry on the show is given a bit of the story of Edric Storm, who doesn't appear on the HBO "Game of Thrones." Storm is a higher-born bastard son of Robert Baratheon. All that stuff about Gendry at Dragonstone doesn't happen to Gendry — it happens to Edric Storm. Except the weird sex stuff with Melisandre, because Edric Storm is 12.
Edric Storm is the son of Robert Baratheon and Delena Florent (Stannis Baratheon’s wife’s cousin). Davos sneaks Storm away with the help of a few other men in "A Storm of Swords" and "A Feast for Crows" because Melisandre has gone crazy for king's blood again, just like how he helps Gendry in the show. As of "A Dance with Dragons" Edric Storm is hiding in Lys. (Maybe Gendry is in Lys in the show? Who knows — as of the show he's still rowing that little boat.) In the books, as of "A Feast for Crows," Gendry is working as a smith at the Inn at the Crossroads where he saves Brienne’s life when a fight breaks out there.