Guys, Shadowhunters is messing with all my favorite couples lately, and it's starting to give me anxiety!

On the Saia side of things, it's hard not to sense an oncoming storm in Simon (Alberto Rosende) and Maia's (Alisha Wainwright) relationship where Jordan (Chai Hansen) is concerned, considering there may be a history between the two wolves. The more imminent threat though comes from Heidi (Tessa Mossey), who spent this entire episode trying to get into Simon's heart (and pants).

Simon was obviously a gentleman and politely told her to take her crazy elsewhere because he had a girlfriend. Naturally, Heidi took that as an invitation to stalk Simon and track down this "girlfriend," who was competing with her for Simon's affection. She ended up tracking him to the Hunter's Moon, where she witnessed him receive a platonic kiss from Isabelle (Emeraude Toubia).

Heidi came to the same conclusion as every Sizzy shipper upon first seeing them breath the same air: there's so much chemistry, they MUST be soulmates! Unfortunately, that meant Heidi was out for blood — literally — and she attacked Isabelle instead of Maia, hoping to take out her competition for Simon's heart.

Shadowhunters: What Is the Praetor?

Simon may have had to turn her over to the Praetor in the end, but we don't think Heidi is quite done with him yet. Though she may be less cuddly the next time we see her...

As for Clace, Clary (Katherine McNamara) finally realized that her boyfriend has been The Owl the whole time, not to mention that Jace (Dominic Sherwood) is no longer Jace because Lillith (Anna Hopkins) stole his love for Clary away. That ship is taking on water fast, I'm afraid.

Harry Shum Jr., <em>Shadowhunters</em>Harry Shum Jr., Shadowhunters

Finally, let's all ask the question no one really wants to say out loud: Is Alec (Matthew Daddario) about to cheat on Magnus (Harry Shum Jr.)?

Alec has not been taking his newfound realization about Magnus' immortality well, picking fights and making snide comments. It's childish, sure, but you have to feel for the guy. He'll never be just another notch in Magnus' bedpost, but one day, Alec will be just another memento in Magnus' box of keepsakes — at least as far as he sees it. That's unfortunately how immortality works.

Magnus' insinuation that Alec's inexperience in the relationship department is what's causing their issues wasn't exactly the best way to respond though. When you couple that comment with Alec's newfound friendship with Underhill (Steve Byers), another Shadowhunter at the Institute who recently came out as gay, it feels like a disaster is imminent. Matthew Daddario told TV Guide that seriously rough waters are ahead for Malec this year, after all, and cheating... well, that's about as rough as romantic waters get.

Shadowhunters' Dominic Sherwood Breaks Down That Clace Twist

Secrets From Set: You can't have an episode of Shadowhunters without a super-powered fight scene, and the one between Isabelle and Heidi was tonight's highlight. "I love it because it's like a girl fist fight!" Emeraude Toubia says.

Fist fights are all well and good in fiction, but in real life, the actors have to be extra careful not to actually land any punches. That creates a few obstacles in the filming process, when you want to make sure your fight looks real without being well... real.

"So the way we actually shoot the punches and stuff like that is you never get too close to the actor," Toubia reveals. "It's more of finding the camera angle that's perfect for the way you're going to punch someone."

From there, it's all about movie magic and pretending to get hit — Emeraude Toubia even gave us her best fake out!

Shadowhunters airs Tuesdays at 8/7c on Freeform.