I would suggest reading the threads tagged "mono/poly." It seems that what you have is a relationship based on someone being monogamous in relationship identity and a person who identifies as polyamorous. In my belief people are born on a scale between only loving one at a time and open sexualyl and loving many. Where you fit and where your partner fits is really important to know.
You say you don't want to set boundaries. Its all fine and dandy for people who are experienced in poly (RA) and know themselves well in that they don't need boundaries (I would argue that it is still a good idea to express what ones bottom line is and ones requests just the same however... we all have a bottom line and need certain things) but I would suggest that you DO set boundaries with someone that is not experienced.
Setting boundaries would mean sitting down and talking out all the things that are okay with you both and just not for both of you; seeing if you can find common ground on some of it. On the issues that you can't find common ground I would see about how close you can get to being comfortable without exploding due to extreme discomfort (traumatizing) and then work your way back.
It might be that there is a huge gap between what you feel comfortable with and need and what he feels comfortable and needs. Such is the case with most mono/poly relationships. This is where a compromise comes in. Compromise is a land where one sits and feels uncomfortable all the time because an agreement just can't be reached right now. It sucks, and sometimes last a REALLY long time, but if you love someone, it is sometimes a better feeling than what it feels like to not be with that person. Its up to you to decide what is best for you on that one and who gets to be uncomfortable. I have noticed that sitting in that place makes everyone feel uncomfortable as its not a nice feeling to know that you are restricting someone just as much as it isn't nice to feel constricted.
I have a mono/poly relationship and there is lots that I and my partner have written here. Have a look at my blog from early Dec 2010 on and you will see most of that journey. And, as I said, look at the mono/poly tagged threads.
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