Following the May 16th episode of General Hospital, social media exploded with a single brash assertion: Cody is the father of Gio, not Dante. That notion spread like wildfire, fueling widespread speculation and an onslaught of fiery debates online. Fans cited Cody's expression when Lulu cornered him with the truth, some say he appeared shell-shocked, others claim he appeared guilty.
One viewer summarised the speculation of a dozen fans by claiming that Cody is the father of Gio and wrote,
"I have said all along that Cody is the father"

Some of his fans noted Cody's response as a tell. According to them, it was not shock, it was realization. Several viewers now believe Brook Lynn might have been with both Cody and Dante at the same time, and either does not know or has never come clean about the whole thing.

On the other hand, not everyone is so sure. Some fans reasoned that Cody just appeared to be surprised because he believed Brook Lynn had terminated the pregnancy years earlier.
They noted that he had never been interested or suspicious of being a dad until now. Those viewers maintained that if Cody really was suspicious, he would have addressed it earlier. A lot of people think that the writers are merely throwing red herrings just to stir the pot.

Some went as far as stating that Gio physically resembles Cody more than Dante. Whether that's true or not, it's a theory that has been gaining momentum in recent times, with Cody and Gio having increasing screen time together.

Recent developments involving Cody on General Hospital
In the latest episodes of General Hospital, Lulu is making progress with her investigation into Gio's past. She brought Cody into the conversation, revealing that she suspects Gio to be the baby Brook Lynn gave up years back.
Cody, surprised by the revelation, admitted that he always believed Brook Lynn had an abortion.
Meanwhile, Brook Lynn is plagued by flashbacks and guilt. Brook Lynn was seen becoming tearful on her son's birthday, the same day Lois is quietly wishing Gio a happy birthday at the same time.
It would appear Lois has more to say than she is saying, as does Cody, who now gets confused about where he stands in the story. There are also rifts between Gio and Dante. Dante scolded Gio for participating in Rocco's beach party.
Gio, being shunned, is still emotionally detached from him. Sonny, however, has stepped in to be supportive of Gio, giving him credit for his efforts even if other individuals do not.
With Lulu's determination, Cody's conscience, or a genetic test, it's more and more likely that this story is setting the stage for a show-stopping revelation, and soon.
Fans can watch General Hospital on ABC.