Hulu’s How I Met Your Father season 1 called back to many How I Met Your Mother iconic settings and characters, but one hypothesized connection between the two TV shows involved Barney (Neil Patrick Harris) being Sophie’s (Hilary Duff) unknown father – here’s that theory explained. Created by Isaac Aptaker and Elizabeth Berger, How I Met Your Father season 1 managed to weave its parent series How I Met Your Mother’s themes and feel into a brand-new story focusing on Sophie and her late 20-something group of friends. How I Met Your Father season 1’s success brought the TV show to be renewed for an even longer season 2, which will have 20 episodes instead of season 1’s ten.

A longer season 2 could provide even more cameos from HIMYM’s original cast, although How I Met Your Father season 1’s Robin cameo already proved that the spinoff is able to balance callbacks to the original series and its own unique style. HIMYM cameos in How I Met Your Father were plenty and included Robin (Cobie Smulders) and Carl the bartender (Joe Nieves), as well as Ted (Josh Radnor) and Marshall’s (Jason Segel) apartment being let to Jesse (Chris Lowell) and Sid (Suraj Sharma). Still, the cameo of Barney in How I Met Your Father was theorized as soon as the sequel was announced, as his many connections around New York could have plausibly led him to appear in Sophie’s story.

Related: Why Barney Stinson Shouldn't Appear In How I Met Your Father

While the various theories regarding a possible Barney cameo in How I Met Your Father saw him ending up in very different situations - including hooking up with Sophie or Barney authoring a Playbook-like parenting guide that HIMYF’s characters would eventually need - a specific peculiar theory gained traction. The theory involved Barney secretly and unknowingly being Sophie’s father, therefore making it the perfect opportunity to principally link the spinoff to How I Met Your Mother while also getting an answer about Sophie’s true parentage. Here’s the bizarre Sophie being Barney’s offspring’s theory explained.

Barney Stinson Is Sophie's Dad: How I Met Your Father Theory Explained

hilary duff as sophie and neil patrick harris as barney in HIMYF and HIMYM

The theory that Sophie’s unknown father could be Barney Stinson was brought forth by some fans on Reddit, but was mainly spearheaded in a video about How I Met Your Father’s popular fan theories on MsMojo’s Youtube channel. The theory primarily hinged on the party girl nature of Sophie’s mother, Lori (Paget Brewster), and on Barney’s propensity to coax women into sleeping with him through various plays, as often shown in How I Met Your Mother. Barney’s playboy attitude could have easily drawn him to Lori, as How I Met Your Father revealed that Lori’s relationships ended up being constantly the wrong ones that made her and Sophie suffer, whisking Sophie from one place to the next depending on the boyfriend of the moment. While Ellie is the only child of Barney Stinson’s that’s been officially confirmed by How I Met Your Mother in season 9, the show abundantly detailed Barney’s frequent one-night stands, so it wouldn’t be too far-fetched to think that one of his paramours could have possibly become pregnant and decided to keep the child without telling Barney.

Why Barney Can't Be Sophie's Dad In How I Met Your Father

Neil Patrick Harris as Barney Stinson

The Barney fathering Sophie’s theory was debunked as quickly as it caught on. While the theory would have beautifully and meaningfully connected How I Met Your Father to HIMYM, it would have been practically impossible for Barney to be Sophie’s father. As How I Met Your Father season 1 established that Sophie turned 30 in 2022, she would have to be born around 1992. How I Met Your Mother had already revealed in season 1 episode 15, “Game Night,” how Barney started having sex only in 1999, therefore Sophie couldn’t mathematically be his child.

Why How I Met Your Father Was Right To Avoid Barney in Season 1

Hilary Duff as Sophie and the rest of the cast of How I Met Your Father

How I Met Your Father used HIMYM cameos sparingly in season 1, with Robin’s cameo in the season 1 finale being possibly its most relevant, both in terms of the original How I Met Your Mother cast and in relation to Sophie’s story. Still, many speculated that the perfect character to appear in How I Met Your Father could've been Barney, as not only he was in New York at the time, but he could have also still been part of New York’s dating scene, despite his change of ways after his daughter Ellie’s birth. How I Met Your Father’s longer season 2 could offer many more chances to see old HIMYM characters in the spinoff, but its season 1 was right in choosing not to include a Barney cameo. After all, Barney was one of How I Met Your Mother’s most distinctive characters, therefore letting him appear in How I Met Your Father’s first season could have risked the spinoff to bet everything on nostalgia rather than developing its style and story. Thankfully, that wasn’t the case, and How I Met Your Father shaped up its own voice without necessarily putting off a future potential Barney cameo.