SMG4: If Mario was in The Sonic Movie is the fourth episode of Season 10 and the five hundred and fifty-sixth overall to be uploaded by SMG4.
This is also the sixteenth episode of the If Mario was in... series. It was aired on February 8, 2020.
The video starts off with Mario sleeping in his go-kart dreaming of him dancing alongside sapient spaghetti. This was until something came passing through him, throwing his go-kart around, and woke Mario up from his dream. Mario went after the strange anomaly (first on his go-kart, then on a plane). It turned out that it was been none other than Sonic the Hedgehog (whom Mario immediately shot) running from Swagmaster69696969696 and Chris Gordman in their tank. Chris explained to him that they were just after Sonic this time until the latter knocked them out and escaped with Mario, but the plumber wanted no involvement with him. According to Sonic, the reason why the military was after him was that he took a walk. However, the Blue Blur's idea of a "walk" was to run around the Earth at top speed, which resulted in a massive power outage. When Mario asked what the former would do next, he declared that they should lay low for a while.
The two mascots then headed to a Blockbuster store, in which the hedgehog said that would be the last place the government would come looking for him. Dr. Eggman was now working as a cashier, until Swag and Chris arrived and asked Eggman for assistance in capturing Sonic. Eggman explained his "adulthood responsibilities" have caught up to him, and he no longer had any ambitions of defeating Sonic. Additionally, he has been paid a very minimum wage ever since beginning his work at Blockbuster, making him very poor. Swag and Chris then promised him a "bajillion" dollars from the government should the mad scientist successfully catch Sonic for them, which got Eggman back in the game after some secret dancing in rejoice. Mario and Sonic overheard the conversation, and now that both the government and Eggman were working together, it seemed impossible to escape from them. Mario then had an idea of how to get the military to stop their manhunt.
In a mall, Swag emerged from a nearby bathroom, singing a song to himself. While he was doing so, Mario quietly emerged from a Starbucks table Steve was on, and tried to anger Swag with a simple insult. However, that didn't work, so the plumber decided to perform a much more triggering insult: declaring that his pingas was bigger than the guard's. This successfully outraged Swag, who grabbed Steve, believing that he was the one who insulted him, even though the latter calmly tried to dissuade him from his rage. In retaliation, Steve kicked Swag into a hallway, which made him hit Sonic wearing a girl's wig. Though Swag initially was irritated at the latter for crashing into him, seeing the disguised hedgehog's face made the guard fall in love with "her" at first sight.
Swag promptly apologized to Sonic, who told him "she" thought that there were no broken bones in "her" body. Before "she" could finish "her" sentence, Swag requested the hedgehog to go out for coffee. Nervous about what to say, Sonic was silently informed by Mario to go along with Swag's offer, forcing the hedgehog to say yes (albeit in an agitated tone). This caused Swag to naturally rejoice in joy, starting the two's "relationship".
Back in Sonic's hideout, Eggman arrived in his Death Egg Robot, about to capture his long-time nemesis. However, he realized that the hideout was empty, so he instead tried many different places to find the hedgehog. Unfortunately, none of the locations had traces of Sonic, causing Eggman to be stumped. He sat defeated at the mall, but he found Swag flirting with the disguised Sonic; Swag was telling his "girlfriend" the events of SMG4: Mario Gets His PINGAS Stuck In The Door, though the guard altered the ending to make it seem like he saved the kingdom and did all of the work. Eggman immediately saw through Sonic's disguise and attempted to capture him with a blaster, but was stopped by Swag's rocket launcher, thinking that the doctor was after his "girl". The doctor attempted to expose Sonic, but Swag merely thought that he was lying and promptly threw him out of the mall. Eggman declared that he will reveal who Sonic truly is, but Mario, after overhearing this, vowed to stop him.
On the first date (which was on a lake in a wooden boat near a bridge), Swag fooled around by adapting a French accent and playing around with a stick of bread and a croissant, but Sonic simply stated that he wanted to die. In the lake's water, Mario was watching the date unfold, but he suddenly spotted Eggman attempting to catch his nemesis using a fishing rod. Not wanting to blow Sonic's cover and ruin the date, the plumber pulled the boat away from the hook, agitating the mad scientist and making him use his fishing rod four times in a row. As Mario continued to move the boat away from danger, Sonic was notably struck with motion sickness and vomited shortly after, while Swag was completely unfazed by the boat's wild movement and believed the hedgehog to be enjoying the ride. As Mario got infuriated by Eggman's persistence, the latter then taunted him for being unable to do anything, which made the former grab a nearby shark underwater and attach it to the hook. This caused it to bite Eggman's head and make him fall onto the boat, and Swag commented on just how "thicc" he was.
On the second date (which was now at a theater), Sonic and Swag were watching a sponsor commercial, but Eggman (in the row of seats behind them) placed a Bob-omb on their popcorn, and Mario, noticing this, decided to prevent this attempt on Sonic's life. Though Swag was ecstatic when he and his "girl" held hands together, the hedgehog was clearly getting more and more triggered by all of the guard's efforts to win his heart. Suddenly, Mario took and ate the "couple's" popcorn, causing his body to blow up entirely. He then thanked the two for the meal before (somehow) floating upwards, but Swag remarked on how people can be so rude nowadays.
On the third date (which was oddly at a playground), Swag was laughing and having fun on the swings, but Sonic was less than happy to be there with him. However, Eggman was on a nearby van wanting to kidnap his arch-enemy when Swag wasn't looking, but Mario wrote "FREE CANDY" on its side. This caught the attention of Mr. Hall Monitor (now a police officer), who blew Eggman up after stating that he was "reaching illegal levels that no one should ever go". Thankfully, Swag wasn't even aware of this occurring, as he was too distracted by his time on the swings.
Finally, they arrived at the final date. Mario told Sonic that the time was now to ask Swag to end the hunt for the hedgehog. The "couple" sat at a table in Papa's Pizzeria; while Sonic attempted to ask Swag to stop looking for him, Swag was far more focused on dating rather than listening. Mario, watching from afar, remained confident that the date would end up perfect, but Eggman suddenly grabbed him from behind and locked him in the kitchen's fridge. Meanwhile, Sonic, frustrated with Swag's repeated attempts to woo him, decided to retreat to the bathroom. Eggman confronted him, but they were interrupted when Mario, still stuck inside the fridge, barged in. Sonic, with his nemesis distracted, knocked him aside and released the fellow mascot. Together, they beat up the scientist and knocked him into the restaurant's interior. As they stood triumphant over him, Eggman then knocked Sonic's wig off.
Just as Eggman finally revealed that the girl Swag had been dating was actually their target, Swag revealed he didn't care if his love was actually a male person in disguise. He declared that it was not the outside that mattered; he still loved him in the inside, even though Swag confessed that his date with Sonic wasn't considered gay if he said "no homo" (which he promptly did). Despite Eggman's protests that Sonic had now been captured, Swag declared that the military doesn't want Sonic anymore and proceeded to bat Dr. Eggman out of the restaurant. Just as Sonic was grateful for no longer being hunted down by the government, Swag then took Sonic on their "honeymoon", walking off into the sunset (much to the hedgehog's chagrin) as the curtains closed on them.
Suddenly, SMG4 appeared and wished everyone a Happy Valentine's Day, until he was just been told that the video was actually about the new Sonic the Hedgehog movie rather than a Valentine's Day special. Though SMG4 got shocked for a while, he wished everyone a Happy Valentine's Day anyway.