Meet Winn's New Alien Girlfriend In Supergirl Featurette for Mr. and Mrs. Mxyzptlk

In the new Supergirl featurette, co-executive producer Jessica Quell and executive producer Robert Rovner preview tonight's "Mr. and Mrs. Mxyzptlk" episode.

So Mon-El is not very happy to have this dashing, charming rival who can just snap his fingers and make anything happen," Quell says. "He gets jealous and his jealousy does not go over well with Kara."

The episode will also feature a super-excited Alex having her first Valentine's Day with Maggie, who happens to hate the Hallmark holiday. "Alex never got to enjoy Valentine's Day," she explains. "This is the first time she's been in a relationship on Valentine's Day and she's really excited to do all of the romantic and kind of cheesy things." She adds, "This is an important episode in their relationship because we learn the real backstory of how Maggie was outed to her parents."

Love is also in the air for Winn. "And Valentine's Day would not be complete without a love story for Winn Schott," Rovner shares, "and we introduce a new girlfriend, an alien warrior girlfriend named Lyra."

When Mr. Mxyzptlk (guest star Peter Gadiot), a magical imp, shows up on Earth and declares his love for Kara (Melissa Benoist), she tries to let him down easy, thinking him harmless. However, he decides it's a challenge and starts to wreak havoc on National City. Mon-El (Chris Wood) has seen beings like Mr. Mxyzptlk on Daxam and knows how dangerous they can be. He and Kara argue over how to get rid of Mr. Mxyzptlk, further straining their relationship.

Meanwhile, Alex (Chyler Leigh) and Maggie (Floriana Lima) celebrate their first Valentine's Day together.

Stefan Pleszczynski directed the episode written by Jessica Queller & Sterling Gates.

MORE: Supergirl: First Look at Mr. Mxyzptlk! / Supergirl Recap with Spoilers - Luthors / Lena Luthor's Secret Origin Revealed

Distributed worldwide by Warner Bros. International Television Distribution, SUPERGIRL is executive produced by Greg Berlanti (Arrow, The Flash), Ali Adler (The New Normal), Andrew Kreisberg (The Flash, Arrow) and Sarah Schechter (Blindspot, The Mysteries of Laura). Supergirl is based on the characters created by Jerry Siegel and Joe Shuster and appearing in DC Comics, by special arrangement with the Jerry Siegel Family.

"Mr. and Mrs. Mxyzptlk" episode of Supergirl airs Monday, February 20 at 8 p.m. ET/PT.