In Riverdale episode 15, which celebrates FP’s (played by Skeet Ulrich) 50th birthday, the show flashes back to the early nineties and specifically, as fans have worked out, 1992 with references to Nirvana’s Smells Like Teen Spirit (1991) and Johnny Depp and Winona Ryder’s relationship (1990-93).
The scene appears to show a 16 year-old FP in 1992, which would suggest that he would now be in his early forties.
Viewers can work out his age at the time because he is seen to be in junior year, which meant he would be 16/17.
So how is he suddenly 50 in the space of 25 years?
One theory is bosses simply made him 50 to tie in nicely with the celebration of the 50th episode of the show.
The CW show is known for its inaccuracies and timing issues but fans have been sent into meltdown by this huge error.
One fan tweeted her shock: “I’m sorry but how is this FP’s 50th birthday if they were in high school in the 90s?”
Another eagle-eyed fan tweeted: “Remember the parents can’t be 50 because FP and Alice have their child in high school. Charles would be 25 meaning FP and Alice and all the parents are about 43/44.”
FP and Alice (Madchen Amick) had their son Charles when they were 16, making FP at least six years younger than 50, which viewers were told he is.
It is safe to presume he was not held back at school for six years and so would have left school shortly after 1992.
This could be proven in season two when FP’s son Charles is revealed to be 25, which means his parents could be no older than 44.
It all just does not seem to add up and is not the first time fans have felt bemused by writers’ choices, though could it simply be an easy mistake?
Fans will remember how in season one Cheryl Blossom (Madelaine Petsch) randomly burned down her house and left fans wondering what the sense behind it was.
But maybe its appeal is that it keeps fans on their toes?
Riverdale fans have been in overdrive recently discussing the show’s future after actor Luke Perry’s death left a huge parental hole in main character Archie Andrew’s (KJ Apa) life.
The absence of Fred Andrews, the character brought to life by Perry, has led for calls to bring back fan favourite Mary Andrews (Molly Ringwald) as Archie’s mother.
Fans were united in being set against recasting the character after Perry’s death in honour of the actor.
Cole Sprouse, who plays FP’s son Jughead Jones, recently revealed on The View that there is a plan to deal with the loss of the character.
He said: “I can’t go too much into the spoilers of it. But we do have something planned narratively.
“We dedicated some of the episodes to him. He was very well loved. I mean, the whole world is mourning his passing.”
Fans will have to wait and see how the show honours Perry’s memory and moves the show on for future seasons.
Riverdale season 3 continues Wednesday night on The CW in the US, and Thursday morning at 9am on Netflix in the UK.