i’ve been poly for a while now, but for the first time i’m in a situation where my bf is also considering trying to be poly, and i’m really uncomfortable with that, but he’s been so supportive of me also having a gf that i dont want to be like, ‘no, only date me’. does this make me, like, a SUPER terrible person?

I don’t know if you’re a terrible person, though I sincerely doubt that you are - there are very few truly terrible people. Most of us are at least a little bit scared, confused, or oblivious, which can make us behave irresponsibly or hurtfully. But no one is a terrible person. Being gentle and self-compassionate with ourselves - while remaining accountable for behaviors and thought patterns that need to change - is often the best way to break patterns of hurt.

But to answer your question more specifically: while that doesn’t make you a terrible person, it definitely strikes me as something that could cause a lot of problems and is worth working through. All he’s asking is to be afforded the same freedoms you asked him to give you, and it seems only fair to do so. At the same time, all feelings are valid, and this isn’t to say you’re obligated to just swallow your discomfort. I think it needs to be worked through, but with the express goal of helping you get comfortable with it. 

Ask yourself: Why are you less comfortable with him dating someone? What are you afraid of, specifically? What do you think will change? What’s your “worst case scenario?” Talk this through with him, and also think it through on your own. You yourself have lots of evidence that a person can date multiple people without losing their feelings for their other partners - it’s there inside your own head, it’s proven in your own experience.

Maybe there’s something you enjoy about the imbalance - investigate your own motives here and figure out why you prefer a situation where you’re poly but your boyfriend isn’t. When you find something, examine it closely to see whether it’s healthy. This sounds like something that’s not only very much worth getting through as a couple, but something that can be surmounted with some honest introspection and communication. Good luck!