Back when I hung out on the polyamory subreddit, it felt like nearly 1/3 of the posts were people saying "I'm new to poly but my partner wants me to open the relationship. Am I horrible & closed-minded for not wanting to do that?"
The thing I appreciated is that the community would rush in to be like "oh, baby, no! Do not be pressured into this. It sounds like you're being guilted into something you're not comfortable with & makes you unhappy."