Ok, so recently I’ve been considering trying polyamory, and told someone who I thought was a good friend but apparently because I’m interested in dating both a guy and a girl, (because I don’t want to ignore/erase anything about my bisexuality) I’m a slut. Don’t know whether to continue this friendship or end things. Help!
First, I have to point out that there are plenty of monogamous bisexuals, and they are not ignoring or erasing anything about their bisexuality by being with one partner. For some people, polyamory is part of their bisexuality or vice versa; and it sounds like that’s your experience - but be careful not to imply that monogamy “cancels out” bisexuality or that bisexuality necessitates non-monogamy. You want to be free to date people of multiple genders, and that’s a completely reasonable reason to be polyamorous, but it’s not an inherent property of bisexuality.
To answer your actual question: only you can decide whether this is a friendship you want to try and preserve. It’s a frustrating fact of life that people we’re close sometimes do and say things that hurt us. Sometimes the healthiest thing for us is to take space from that relationship to honor our own safety. Sometimes the healthiest thing is to try and take a communicative, restorative position and attempt to heal and resolve the issue.
If you want to end the friendship, that’s totally your right; you’re not obligated to stay close to someone who calls you names or shames your identity and choices. If you want to try and talk things out with this friend, let them know that you don’t appreciate being called a slut, and that you’re not asking them to be polyamorous yourself, but to be understanding and accepting of you. You can explain that you shared these thoughts with them because you hoped they would be safe and helpful, and then let them know what they can do, specifically, to be safe and helpful in the future.
You can also make space for their questions, confusion, or discomfort - just saying something ignorant doesn’t make someone an irredeemable bigot, so do your best not to be shaming or accusatory. Give them the benefit of the doubt that they don’t want to be intentionally cruel, and are willing to try and understand if given another opportunity and a gentle nudge in the right direction. Be open and willing to explain how you feel and the truth of your bisexuality and non-monogamy, and be patient, since no one is going to get everything right all the time.