I very much understand your desire for both stability and variety. I feel like I have the best of both worlds in that my husband and I are exploring non-monogamy together. It's not that common, I don't think, but we only see other people together. That means threesomes and foursomes, but also that we get those bonding moments together, even when they are with others. I do find it beautiful and something that feels very natural to us both. I sincerely hope you find what you are seeking. I just wanted you to know that it is possible.