This is an old thread, but I thought I'd share my thoughts.
Though I am not with the couple I was with back in the spring/summer, I still learned a lot from the experience. Affection was not as big of an issue as I thought it'd be. It was just really natural. Even if I was not cuddling with them, it still made me happy to see them cuddling and smiling. Their love only made me love them more. It was just very easy to go with the flow and realize that there was no intentions of any of us getting more affection than another.