Threesome as a couple

My bf38 and I f28 are 6 month dating, and I’m relatively open to bring other people in our sex. He was the first to propose threesome, and I agreed if it would be another man or woman (I’m bi), but he insists that it should be woman only cause he would be jealous to a guy…. Im curious cause he seems to be very confident about himself. And also I feel a bit inequality in his request. Like later he told me that he would be dating me even if I’ll make a sex change surgery. But he also states he is hetero. He had experience MMF and MFF, and I haven’t neither. Im confused 🤯