I would say while that scene was the biggest problem, over the whole ep4 there where many problems.
At begin, both are like MC don't leave ect...after that i had expected some kind of fight, at least a heated argument...but nothing instead their all smiles after like 2 min mc left.
The following days, there's zero sign that they where close to break up, had a fight/argument...
At the party Josy want MC to talk with them, first thing u come in the room and they seem all over each other...feels kinda like a other slap in mc's face
Then what Bacchus said, that love confession there was just out of place and all infront mc
And than as u said, if u choose to stay friends, the whole scene basically screams they give a fuck for mc's feelings.
Probaly just me...maybe better if u have such a talk not if ur full drunk, high and just fucked Quinn on the roof