Supergirl: 12 Episodes Every Sanvers Fan Should Watch

Ahead of season 2, executive producers Greg Berlanti and Andrew Kreisberg revealed that a character on one of their four superhero shows would come out. It wasn't long before Supergirl's Alex Danvers (Chyler Leigh) discovered her sexuality after befriending science cop Maggie Sawyer (Floriana Lima) — and thus "Sanvers" was born. Whether you're a fan of the relationship or a newbie looking for a good primer, we've gathered the 12 best episodes that encapsulate their relationship, from Alex's emotional coming out to her proposal to Maggie.

Maggie Sawyer makes quite the debut, butting heads with Alex as they both investigate an assassination attempt on President Marsdin (Lynda Carter). As the duo works the case together and Alex must save Maggie's life, it quickly becomes clear that the chemistry between them is electric.

Sparks fly when Maggie and Alex go undercover at an alien fight club, culminating in Alex asking Maggie out for a drink but Maggie revealing she has a date with another woman.

After Maggie and her girlfriend break up, Alex tries to cheer her up, leading Maggie to believe Alex may be gay. Though Alex initially denies it, she comes to realize what Maggie said might be true, culminating in a passionate and honest confession both to Maggie and herself.

Encouraged by Maggie, Alex comes out to Kara (Melissa Benoist). Though there's some initial weirdness, Kara admits it's because she never gave Alex the safe space to talk about this. Alex then makes a play for Maggie by kissing her, but Maggie turns her down in a heartbreaking scene that nearly sends Alex running back into the closet.

After being shot down, Alex initially tries to push Maggie away, finding it hard to now be her friend. But Maggie ultimately expresses that she truly cares about Alex and couldn't imagine her life without Alex in it, so they take a step toward being friends again.

In the final episode before the winter hiatus, Alex finally comes out to her mother Eliza (Helen Slater), who immediately supports her. After getting injured in the line of duty, Maggie ends up admitting that she does have feelings for Alex and they kiss.

After Kara gets trapped on Slaver's Moon, Alex pushes Maggie away, believing that anytime she's happy, something bad happens. Ultimately, Maggie reveals she knows Kara's secret identity, so there are no secrets between them — for now.

In one of the more comedic moments of the Sanvers relationship, Kara, Winn (Jeremy Jordan), James (Mehcad Brooks) and J'onn (David Harewood) gather at the bar to meet Alex's new flame and are surprised but supportive upon discovering that it's Maggie. J'onn, being a psychic, already knew. And Mon-El (Chris Wood) is unaware that ladies loving ladies is anything but normal.

Excited to be celebrating her first Valentine's Day with a girlfriend, Alex is disheartened to hear that Maggie hates the Hallmark holiday. After Alex's attempt at making the day special fails, Maggie reveals she hates V-Day because when she was outed as a child on Valentine's Day, her parents kicked her out of the house. When Kara explains to Maggie what the holiday means to Alex, Maggie throws a special themed dance for Alex.

After Maggie and Alex run into one of the former's exes, Alex learns that Maggie had cheated on her, which leads to a very frank discussion about trust.

When Alex is abducted, Maggie is prepared to break the rules to free her, but Kara keeps her from crossing the line. When it appears they may not find Alex in time, Alex and Maggie have a heartbreaking video conversation where the latter says she wants more firsts with Alex. Her wish is granted when they save Alex and the two declare their love for the first time.

In the season finale, after surviving the Daxamite attack, Alex proposes to Maggie. We don't see her response, other than a big smile on Maggie's face, so presumably it's good news — we hope.

Supergirl season 3 kicks off on Oct. 9 on The CW.