Deadpool is currently in the process of coming to the Marvel Cinematic Universe. However, it's not entirely clear how or where Wade Wilson will make that transition. Given the character's history, it would likely be in an X-Men adjacent project. But there's actually another rumored storyline being adapted for the MCU that could be an unlikely (but great) place to introduce him.
On top of being a good showcase for his style of comedy and physical skills, inserting Deadpool into a potential Secret Wars adaptation could also find some uniquely compelling drama by also adapting his short-lived romance with the Wasp.
Deadpool's Secret Secret Wars by Cullen Bunn and Matteo Lolli focuses on the events of the original Secret Wars -- with the twist being that Deadpool is retconned into having been present at the event. The story sees Deadpool is among the heroes selected to take part in combat for the enjoyment of the Beyonder. Deadpool's intervention quietly impacted the event in multiple ways. Despite his general behavior annoying the other heroes, Wilson proved himself repeatedly -- saving Captain America from Kang, infecting the Venom symbiote with madness, and helping save all the heroes at various points. After being "healed" by Zsaji, Wade's appearance was even restored -- giving the typically scarred mercenary a handsome new face with unmarred skin.
It was with this restored appearance that Deadpool found some unlikely love with another one of the heroes -- Janet Van Dyne, aka the Wasp. Amidst all the chaos of the event, the pair ended up spending a night together, forging a surprising bond. After Deadpool's healing factor allows him to survive the fully empowered Doctor Doom's assault, he reluctantly convinces Zsaji to restore everyone else -- notably including the Wasp, whom Deadpool has seemingly developed feelings for. But his own conflicting emotions for Zsaji left him guilt-ridden with the effort to save the assembled heroes cost her all of her life-force. This in turn undid her healing of Deadpool -- leaving him restored to his typical scarred visage. This inadvertently horrified Wasp, leaving Deadpool heartbroken and Wasp disguised with her own vanity.
As a result of the Beyonder's lingering energies, Battle-World quietly granted final wishes for the heroes -- including for the Wasp. Secretly (and accidentally) wishing she could just forget about her brief romance with Deadpool was amplified, and erased everyone's memory of Deadpool's presence in the conflict. It's a tragic reflection on Deadpool's habit of being a hero and not getting the full credit he deserves for it. But it's also a potential way to introduce Deadpool to the greater MCU. Ryan Reynolds' live-action incarnation of Deadpool is currently in the process of being brought into the MCU. Meanwhile, an adaptation of an unspecified Secret Wars has been rumored to also be in development with the studio.
If the MCU adapts the original Secret Wars, they could use the gathering of heroes to introduce plenty of new faces. Among them could even be Deadpool, giving the Merc with a Mouth a major chance to shine alongside his fellow MCU heroes. He could even be given a potential romance with the Wasp of the MCU -- i.e. Evangeline Lilly's Hope Pym. Pairing the two together even just as potential romantic partners could set up Wade to have further adventures alongside the Avengers and their allies instead of being tied primarily to the X-Men. It could also give Reynolds' Deadpool some surprising drama to play with, especially considering his connection to Zsaji. While it might be unlikely, bringing Deadpool into an adaptation of Secret Wars could quietly be the perfect way to get him into the MCU.