We don't live together but we live near each other. We have date nights in different combinations most weeks. My girflriend and I have a date while our boys have boy time together, then the next day I go out with our boyfriend and she goes out with my husband. We also spend a good chunk of the weekend together, depending on family obligations. We go to some events together, as well, and share a lot of friends, so when parties happen we get to see each other. We try to balance it so that each couple also gets enough time together, and alone time for each person as well. It can be a little chaotic but it is fantastic.
None of us has any kids. That's way down the road for us. I'm 22 and my husband is 24. We've always liked the idea of raising children with more than two parents, but we won't be ready for kids for at the very least five or six years.