but he was really good in understudy rehearsals

HS School Play AU

Here’s the layout; The schoolstuck highschool everyone attends is putting on a production of Romeo & Juliet , not the original version, but a more romcom modern version as opposed to the Shakespearean tragedy, this one is way more upbeat and has no real death (honestly just think Gnomeo & Juliet but not they’re not gnomes). 

Karkat is deadset on being Romeo, romcoms are his thing, but he’s beat out by John, who only really joined for shits and giggles but ended up doing pretty good. Karkat’s totally defeated, and trying as hard as he can not to murder John, but he still get’s to be the understudy. So what else is there to do besides seek help? And the best person to get it from would be the director of the play, Dave, who sets up some extra time after rehearsal for just Karkat. Basically, Dave and Karkat are all alone in the theater, as Dave helps Karkat improve his acting on the big romance scenes, he finds that he’s getting really sucked into Karkat’s act. Like, really sucked in, he’s starting to get lovestruck. 

On the other hand, Rose is Juliet and Kanaya is the costume designer. Rose’s performance is amazing, she’s really convincing as Juliet, enough so to make Kanaya a little jealous. Even if the whole thing is just acting, and Rose is still for sure a total lesbian, Kanaya can’t help but feel a little bad seeing her girlfriend act so convincingly for her love of someone else. Sure, she’s just a good actress and John is acting too, there’s literally nothing else going on besides that, again, she’s fucking gay. Kanaya starts to feel a bit guilty for not feeling as happy for Rose as she should. 

On production night, John gets sick and he can’t come, so Karkat actually has to go on stage as Romeo, he’s nervous though, until Dave tells him to just pretend that it’s only him out there. Meanwhile, Kanaya’s feelings are all the same, the fact that the actor changed didn’t make a big difference, it’s the same act and character, it’s Rose’s part that she had an issue with not John’s. Karkat and Rose put on a pretty good performance, until Karkat starts to choke during the big romance monologue, the same one he gave Dave when Dave started to fall for him. 

In a moment of quick thought, what else was the director to do but try to go on stage and save Karkat from utter embarrassment, the poor guy looked like he was about to cry. Dave jumped onto the stage, and whispered to Karkat to just give the monologue to him. And Karkat does so, leaving the audience confused, why was Romeo giving the romance speech to this random dude? What about Juliet? Karkat started to improve an act, but people were still concerned, in a moment of quick thought, again, Kanaya had the same idea as Dave, and she ran out there to save things, this time, improvising a romantic confession to Juliet, while also telling Rose her feelings about the play while still in character, so they work it out by acting as Juliet assures Kanaya’s character she loves her. 

They improv the rest of the play to the best of their abilities, and it was kinda shitty, but it was a new take on an old story, Romeo And His Boyfriend & Juliet And Her Girlfriend. It wasn’t the best play ever but hey, they did it, and they went back to see John while he was sick at home to tell him everything, he only wishes he was there to see it.

TL;DR: John gets Romeo in the school play but Karkat wanted the part, instead he’s John’s understudy. Dave helps Karkat improve his acting as the director and starts to fall for Karkat. Rose gets Juliet but she’s such a good actress that it makes Kanaya a little jealous, even thought it’s all pretend. On the night of the play John get’s sick and can’t come, so Karkat goes on but starts to choke. Dave and Kanaya go on stage and start to improv to save the performance. Juliet ends up with Kanaya’s character and Romeo ends up with Dave’s character.