There is a website for swingers and people in open relationships also a few poly groups too on Facebook.
https://www.swinglifestyle.com/ and
www.sdc.com Open marriage can have a different meaning to each person differently as long as you and your partner both agree with your choices and limitations and never compromise yourselves to make the other person happy because you only end up resenting the other person and being in the lifestyle. I have found it’s very important to communicate openly and always respect each other and if there is gonna be jealousy then don’t even attempt to be open.