Comic book marriages are a lot like comic book deaths - they're often used as plot devices and are almost always temporary. Though some classic spousal couplings have stood the test of time, far more fall into the category of “unexpected comic book weddings" at best and cheap gimmicks that were always doomed to fail at worst.
Some say superheroes and marriage just don’t mix, as it’s difficult to write a character who's dedicated to both their partner and their world-saving duties. For this reason, Marvel relationships and DC romances have largely been avoided - especially with major characters - though there is definitely a bevy of strange, sometimes uncomfortable exceptions to the rule.
The relationship between Harley Quinn and Poison Ivy was once relegated to jokes and insinuation, but the fanbase's positive reaction eventually convinced DC Comics to make it canon. While there’s now a very clear romance of some sort between the two in their modern adventures, a version of the characters from an alternate timeline took things one step further and got married.
The Injustice comics, based on the popular video game series of the same name, feature a timeline in which Superman takes over the world as a questionably-benevolent dictator. It’s also a universe in which Harleen Quinzel and Pamela Isley are secretly wed by an Elvis impersonator in Vegas and have stayed married ever since.
Despite the presence of Nakia in the Marvel Cinematic Universe, T’Challa is one of those characters who doesn’t really have a “classic” love interest in the annals of Marvel comics. The Black Panther’s best chance at true love comes when he marries the other most prominent African superhero in existence, Storm of X-Men, in the midst of Marvel’s Civil War. The event is so momentous, the factions led by Captain America and Iron Man agree to temporarily lay down their arms to celebrate.
At first, the royal partnership between T’Challa and Ororo Munroe is a happy one, but the couple is irrevocably divided by the events of Avengers vs. X-Men. This convinces T’Challa to use his influence to have the High Priest of Wakanda annul their marriage - though the two still maintain strong feelings for one another.
Clint Barton is well-known for his career as Hawkeye of the Avengers, but his long-time spouse Bobbi Morse is less recognizable. She’s also been an Avenger (codename Mockingbird) on several occasions, but her most significant appearance is probably a recurring role on Agents of S.H.I.E.L.D..
The Hawkeye of the Marvel Cinematic Universe and TV’s Mockingbird aren’t connected by anything other then their mutual employment at S.H.I.E.L.D., but the two characters enjoy a lengthy - if troubled - marriage in the pages of Marvel comics. Like many comic book marriages, theirs ends when Bobbi apparently loses her life, and although her demise has since been proven a hoax, they have yet to tie the knot again as of 2019.
Few comic book marriages last long enough to produce a child, but the union between the mutant Avenger Quicksilver and Crystal of the Inhumans - which occurs in Fantastic Four #150 - is one of the rare exceptions. Though their background gives a bit of Romeo and Juliet flair to their relationship, Pietro and Crystalia share a loving marriage and give birth to a daughter, Luna.
Tragically, their story wasn’t destined for a happy ending. When Crystal has an affair with an ordinary human, Quicksilver loses it and begins to return to his villainous ways. It marks the end of their marriage - and of Quicksilver’s status as one of Earth’s mightiest heroes - for a while.