Mr. Mxyzptlk Strips Mon-El in New Supergirl Sneak Peek

Even though he just met the magical imp, you can understand why Mon-El immediately dislikes Mr. Mxyzptlk. This is because the being from the fifth-dimension arrives just as Kara and Mon-El are about to kiss for the first time, sealing their new relationship. Oh and it also doesn't help that Mr. Mxyzptlk's introduction includes a marriage proposal to his soon-to-be girlfriend.

"First, let's set the mood," Mr. Mxyzptlk says in the clip. "Candles! Then, music! Next, flowers! And for the pièce de résistance, the ring. Kara, sweety, it's like I said: I'm your one true love, your soulmate, the one true pairing - the kids say. My name is Mxyzptlk and I love you, Kara Zor-El. Tell me, will you marry me?"

An angry and jealous Mon-El tries to use his super-strength to remove Mxyzptlk, but he is no match for the powerful imp, who strips the Daxamite of most of his clothes and teleports him to the DEO headquarters.

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.