I'm gonna try and not write your reactions since everyone has a different reaction to horror movies. For example: I love them and will grin when a character dies while my friend will hide her face in a pillow and yell she wants to watch something else.

Marinette:

She will be hugging you, hiding her face whenever a scary scene comes. Halfway through the movie, she will be whining how she wants to watch something else or she will have nightmares.

Ladybug:

She will have more courage and less fear as Ladybug, but that does not mean she will like horror movies. She will still hold your arm tightly, flinching whenever something scary happens.

Adrien:

He will try to act as if the horror movie isn't scary, but how he flinches and clenches your hand gives him away. If you're also scared of horror movies, will both cuddle with a blanket tightly around you two as if it will protect you two from a murderer.

Chat Noir:

He will be more busy holding you and giving you kisses to even notice the killer in the movie. When you tell him to stop it and pay attention, he will pout and watch the movie. One time he hissed when a jumpscare came and till this day you still tease him about it.

Alya:

She loves to have movie nights and each time will be a different genre of movies. Sometimes it's horror movies, which she likes. If you're scared of horror movies, she will take horror comedy movies like Gremlins, Scary Movie and Beetlejuice. She will usually make fun of the movies if their bad and then write a review of it online.

Nino:

He will keep saying how he would survive the movie, but you usually have a different way, which usually leads to an argument about what way is smarter. Both love to watch horror movies and make fun of the characters.

Chloe:

Nope, she hates horror movies and you won't be able to convince her to watch it. She hates showing weakness and usually during scary movies she will be flinching, maybe even crying in fear and hugging her teddy bear, so no way you're allowed to see that.

Nathaniel:

He likes horror movies so he will sit there with a smile while eating snacks. You will be a bit worried to why he is smiling like a psychopath at the screen. When he asks what's wrong, you will just give him a quick smile and say nothing. Afterwards he will usually be drawing horror-themed drawings for a while, having gotten inspired.

Luka:

If you're scared of horror movies, he won't force you to watch them, but if you do, he will be glad to hold your hand and chuckle whenever you flinch before assuring you it's okay. If you love them, he will be glad to watch as many of them as you want.

Juleka:

She loves horror movies. Whenever you two watch a movie, you better know it's gonna be a horror movie. She will sit there with a small smile while chuckling and stuffing her mouth with popcorn.