Thoughts on having more than one non-barriered sexual partner

Hello everyone. I recently learned there are a handful of people in my community who engage in non-barriered intercourse by default (sex with multiple partners without condoms).

I try to keep to only one non-barriered partner, to minimize any STI spread that may occur. Though testing is important, there are risks that 1. A test may be wrong, and 2. An infection can be introduced and spread after a successful clean test.

Also, my partner has a history of getting BV if her non-barriered partner(s) have other non-barriered partners. So, we keep it to only one non-barriered partner (for intercourse).

Any thoughts on this? Is it ethical to have more than one? Is it sustainable to only have one?