Most Helpful Guy
Open relationship = more than one hole to stuff or more than one stuffer to stuff you. Sometimes you prefer soup, sometimes you prefer salad so it is just a matter of waiting until he prefers you again or say goodbye and done with it and focus on your own harem.
Most Helpful Girl
Sorry to say but you are just one of those girls to him. He doesn't give a damn about your feelings. You can't do anything about it.