This was when I was unsure of myself in my transition and I will refer to this person in a gender neutral manner.
I had an ex who was into polyamory and on paper it sounded good. One of the first dates we went to a restaurant and they immediately want to flirt with someone else. They would always show interest in other people even on dates and everything was about sex. Other sexual partners of theirs would insult me because we were together. I was starting to get more uncomfortable with polyamory.
Later on we got involved with another polyamorous person who clearly was only interested in them. She was extremely rude and yelled at me at one point. My ex would ignore how she treated me. I started dropping hints of breaking up and my ex made me think they would change. They went on lying and cheating and when I found out, they accused me of being bipolar and immediately had a list of people they would date after me. I always asked their input before I made big decisions but I clearly didn’t get the same courtesy despite being accused of using them.
Now I know this isn’t all polyamorous people and I’ve been much happier without my ex. A fog lifted after they left and I feel sure of myself and the love for my hobbies again. Was I being gaslit?
Whether or not you were specifically gaslit or not isn’t terribly clear in your examples. If they were routinely trying to make you feel like you were the wrong one because “this is just how polyamory is” or denied things you witnessed happening on those dates as things either didn’t happen or that your reaction was over the top towards them that would be a form of gas lighting. The implication that you are bipolar is sort of gaslighting but… Not exactly subtle. Pathologizing someone has moved to sit more in the more general “dick move” category in popular consciousness but what it functionally attempts aligns with the aims of gaslighting so whether you want to count it or not is kind of up to you. Not all lying is gaslighting and gaslighting isn’t really more effective lying. Bad technique makes it ineffective and so obvious it doesn’t fit with society’s veiw of gaslighting being this kind of mastermind gambit so I find it more useful to distinguish gaslighting less in terms of how or how well it is being implemented but rather by what the person intends to achieve by it.
Basically as long as the person is ATTEMPTING (success or failure is irrelevant) to make you question and doubt that you yourself are a reasonable human with reasonable reactions who makes logical decisions and sane observations because to do so benefits THEM in some way at cost to you…they are gaslighting you.
If they legitimately do these things out of an actual concern for you and not just a way to try to absolve themselves of any responsibility for bad action and intent it is not really gaslighting… It’s a couple of assholes who don’t know what a healthy relationship is supposed to look like. Gaslighting requires deception which makes it kind of hard to prove if they stick to their guns that everything they did was sincere.
The vast majority of gaslighting works by establishing a false made up version of " normal" and then tries to tell you or demonstrate to you that you fall outside it. You are being told you are unreasonably jealous or forgetful or emotional to the point where the average person would find you difficult to empathize with. To actually be effective it usually needs to sever you from feedback from other people who can tell you that this version of “normal” they are trying to establish is actually complete horseshit.