My partner and I got into a semi heated discussion about being able to love other people equally to your original partner. I’ve also had multiple issues with her being inappropriate in some way with other people. I really don’t want a poly relationship, especially when her extras are hidden. I’d be open to us choosing to find someone together, but I can’t help but feel this is wrong to deal with.
There is a separate issue in just about every sentence here, so I’ll try to break this down.
When you say you had a heated discussion about “being able to love other people equally to your original partner,” what made that discussion heated? Do you believe being able to love multiple people in the same way is impossible while she believes it is? Why did this difference create so much tension - is it possible that both of you may experience love differently? Is the argument about whether such a thing is ever, objectively, possible, or whether it’s possible for you? Remember there’s a difference between “I can’t do that” and “that is not possible.”
When you say she has been “inappropriate” with other people, what does that mean? Is it behavior you consider cheating or borderline cheating? When you got upset with that, how did she react? Is she trying to stay within the boundaries of your relationship, or insisting that what she did wasn’t inappropriate and you need to get over it? Do both of you agree on what you two have a right to ask and expect from each other?
You say you don’t want a poly relationship - that’s fine! If your partner does want one, that might be a problem. One of you will need to make a compromise, or you may need to decide not to continue this relationship if she wants to be poly and you do not. When you say you especially don’t want a relationship if her “extras are hidden,” does that mean she is currently seeing other people without your consent and hiding it from you? That is cheating, not polyamory. Or does it mean that what she’s proposing is a “don’t ask, don’t tell” kind of open relationship, and you’re not okay with it? If you’re not okay with something, you don’t have to do it.
I’d caution against “finding someone together” - that is called “unicorn hunting,” and while it can work well for many people, it doesn’t go well if all people aren’t on the same team. If you’re only agreeing to this because it’s something you can hold your nose and stomach, and you still don’t want her to care for anyone “equally” compared to you, that creates a bad situation for the person you try and date together. If you’re not feeling like she respects your needs in a relationship and you don’t want to be with someone who sees other people, and she insists on doing this with (poly) or without (cheating) your consent, this may be a relationship dealbreaker.