Hi 2gether, We had the same problem when we were in talks about swinging. But it was hubby who was concerned about it and I thought "I need to kiss" as kissing really turns me on. Anyway we had our proper first MFM a few weeks ago and we agreed that kissing was ok but when we were all together I think I had a mental block or something and I didn't really want to kiss him but thought the experience we all had together was great! ( Deep down I still had what hubby told me in the beginning) Well later hubby mentioned it again and said "I really don't mind you kissing" as he was comfortable with it and the next time we all got together wow it was brilliant.
So I think you should both go with your own instincts and also do what feels comfortable for you both and as time goes by the rules you have together will change.
4forfun (mrs)