I am recently divorced from my sole mono relationship in the last decade, so where I am now isn't relevant. It will be a good while before I have emotional energy to date, so let's look at my past.
I've been in San Francisco and Boston. They were absolutely culturally different, but there still wasn't a 'standard' way to be poly. It's all about communication. You have to TALK extensively about comfort zones and boundaries. Anything you agree on is okay, but be honest with them and yourself about your comfort levels. It's okay to be uncomfortable! I am also just...not a jealous person. Over time I did occasionally trip over things that bothered me, and they were usually weird things that took a lot of introspection to figure out the root of. Don't be surprised if this happens even YEARS into being poly. It's normal.
For example, my partner fucking whoever was fine. I didn't like it when they took a date somewhere special to me somewhere I introduced them to or one of my favorite haunts. I'm one of those people who finds a lot of niche places and then spends a lot of time there. It felt like having a sanctuary invaded. As I got to know my metamour this would often change, but it made me disproportionately uncomfortable to share my favorite coffee shops/ restaurants/concert venues that my partner only knew about because of me with someone I don't know well. We talked about it and didn't share those places. Some people have preferences for not bringing lovers to a marital bed, I have my weird quirk.
It's okay to be uncomfortable, or not uncomfortable, to work through it or not. People change over time, too. It's always a process of discovery.
I do not let people drag me into arguments about how I live my life. I am too old and tired to give a fuck about that sort of petty judgement. I will explain once, or give the curious book recommendations on ethical nonmonogamy.
To avoid circular arguments do not JADE. Justify Argue Defend Explain.
https://outofthefog.website/what-not-to-do-1/2015/12/3/jade-dont-justify-argue-defend-explain