Danny was a good dad to DJ, Steph, & Michelle in Full House, but he may not be their biological parent, with one theory suggesting they're Joey's.
Joey (Dave Coulier) may be the father of the Tanner daughters and not Danny (Bob Saget) in Full House according to one dark theory. The ABC family sitcom debuted in the late '80s and ran until 1994. Over time, it became a cult classic, so much so that a spin-off series was greenlit by Netflix, called Fuller House. The events of Full House were kicked off after Danny was suddenly widowed and left to raise three young kids on his own. Luckily, he got help from his brother-in-law, Jesse (John Stamos), and close friend Joey Gladstone.
While the Tanner household wasn't traditional in the sense that there's really no maternal figure, each of the three adults played an important role in raising DJ (Candice Cameron-Bure), Stephanie (Jodie Sweeting), and Michelle (Mary-Kate and Ashley Olsen). Danny was strict but gentle. He embodied the idealized father who not only worked for his family but was also hands-on with his kids. Somehow, he balanced out Jesse and Joey who were more laid back in terms of rules. Danny did date after the death of his wife, but throughout the events of Full House, it's clear that his priority was his kids.
So, it's quite distressing to learn about a popular and dark theory about the show. Apparently, there are some who are convinced that Danny isn't the girls' biological dad, but comic uncle Joey Gladstone. There are a couple of clues backing up this idea. Firstly, it's a tall order for Joey to put his life on hold to help his friend in raising his children full time. Granted that they are best buds, Joey's enthusiasm and dedication to the Tanner girls are still out of the ordinary. He could've just offered to babysit rather than move into their house permanently to look after the kids. Secondly and potentially the most important proof behind this running speculation comes down to genetics. Danny has dark brown hair while his Greek wife was blonde. Based on scientific studies, there's only 12.5% that sport blonde hair, which DJ, Steph, and Mary-Kate and Ashley Olsen's Michelle all have. Now, if both parents are blonde, then the chances that all kids have the same hair significantly increase.
Assuming that Joey is really the father of the Tanner kids, how did this happen? There's really only one plausible explanation that makes this worse — Pam had an affair with Joey behind Danny's back. Not much is revealed regarding the dynamic among the three of them before Danny and Pam got married, but given his close friendship with Joey, chances are that they hung out all the time. This could've resulted in Pam developing some romantic feelings for her then-boyfriend's pal. Maybe Danny, who married Teri in Fuller House, even found out about it eventually, but he decided to forgive them and take the kids as his own; after all, Joey didn't really have the financial means to raise a family at that point. It's a dark idea, and it changes how one views a rather lighthearted and family-friendly sitcom like Full House. But based on the aforementioned points, it is not exactly out of the realm of possibility.
Otherwise, perhaps Joey's just a loyal and helpful friend. By then, he's not exactly busy with anything else in his life since he didn't have his own family yet. Considering the fact that he lived in a fairly nice house without having to pay rent, helping out with Danny's kids in Full House seems like a fair exchange.
