I too am new to this poly thing. JC is visiting his first "other lover" and I still don't know if I will develop any poly relationships. But I have learned really quickly that you have to be open with your feelings. Don't keep them cooped up as they will just fester. I learned that while I like Bee (JC's other) and she and I have become good friends, I don't like hearing her text him all the time! mostly because I wish she would text me more.
After dealing with listening to his text tone go off all day for many days, I realized it was much easier for me to ask him to turn it to vibrate and be discreet when he replied. it was simple but made a big difference on my feelings.
I realize that your feelings aren't that simple, but the premise still stands. Be open with everyone! just make sure you don't jump down their throats but have a calm conversation.
Good luck and keep us posted!