Although Mon-El (Chris Wood) was boarding a pod from Kara’s (Melissa Benoist) home planet, Krypton, when he crash-landed on Earth in the Season 1 finale of “Supergirl,” the two alien refugees aren’t really friends with each other.

During a recent Q&A session with a group of reporters, executive producer Andrew Kreisberg revealed that the Kryptonian and the Daxamite actually have “innate hostility” for one another.

“We’re going to explore, in our universe, the idea that Daxam and Krypton were sister worlds, but they didn’t really get along,” Kreisberg said (via Collider). “It’s sort of the Hatfields and the McCoys. There’s a lot of innate hostility that Mon-El and Kara have for each other, simply because of their backgrounds, which is interesting. Kara is not exactly on her best behavior, and we always think Kara is so interesting when she’s flawed.”

Kara’s “innate hostility” for Mon-El is probably one of the reasons why he is going to be the prime suspect in an assassination plot against President Olivia Marsdin (Lynda Carter) in next week’s episode, entitled “Welcome to Earth.” According to the synopsis of the episode, an attack is made on President Marsdin as alien vs. human rights becomes a hot topic in National City. While Alex (Chyler Leigh) and Detective Maggie Sawyer (Floriana Lima) team up to investigate the attack, Kara spends her time looking for Mon-El, whom she thinks may be the one responsible for the assault.

Despite the trust issues between Kara and Mon-El, Kreisberg previously said that the Girl of Steel is actually going to be a mentor of sorts to the Daxamite.

“What’s interesting about Mon-El joining the show, from Kara’s perspective, is that Kara has spent her whole life as someone who’s been mentored, first by her mother, and then by the Danvers and Superman and Cat,” Kreisberg said (via Collider) at the TCA summer press tour in August. “Now, with Mon-El, he’s fresh off the boat. As far as he’s concerned, living on another planet happened yesterday, and suddenly, he’s on Earth and everything he knew was lost, just the way it was for Kara, but she’s had 12 years to process it and he’s struggling with it. So, Kara is now the one in the mentor position.”

“Supergirl’s” next episode airs on Monday, Oct. 24 at 8 p.m. ET on The CW.