Originally Posted by kingtone
I think something else you may need to be prepared for is that even if your boyfriend is accepting of open relationships and polyamory, he may still place the restriction of you not sleeping with his close friend as part of him entering to this with you. When I began my open relationship, my partner and I sat down together and drew up what we call the "do's and don'ts' a list of rules to help us as we moved from a traditional relationship in to poly. Just remember to be open and honest with each other, hiding things will only hurt both of you.
having a list is a great idea, just remember to keep it fluid and changeable I think... this is why we call them boundaries rather than rules... they can be more like compromises almost, until the "line" is known where it is not enough or too much to take on and crosses over into uncomfortable... this will likely change through time, so updating every now and then is often necessary.