While you can of course persue romance with the cast, the main focus in Call Me Under is the story. Our cast are all incredibly well fleshed-out and written in a way that ensures they are not simply 'just' love interests, they are their own individual characters with detailed backstories and secrets, and have complicated lives which include some of them having relationships (not all romantic in nature) with each other. The poly pairings are not already established either, they are either budding or mere flirtations unless you choose to pursue them together.
We have poly people on the team and have always strived to ensure our poly rep is as natural as possible, especially when the rep for these kinds of relationships in media is often so badly misrepresented. If you choose to persue one of the characters who is part of a potential poly pairing as an individual romance, as with ALL of our games, there will be no awkwardness, jealousy etc. Again, that isn't something we wish to portray, and we've always had wonderful feedback about the way we handle those romances.
The MC is not a third wheel, but a new face/fish out of water in a city where the story makes it clear that they need to find their footing and establish themselves to understand and unpack what is happening.
We really hope you can still enjoy the story despite feeling this way!