((I'm polyamorous, and have multiple partners, Del does not, and would probably make a very distressed and confused face at the idea of doing so.
Polyamory is defined by informed consent of all partners involved.
I have a boyfriend, and I have a girlfriend, and while they are not romantic with each other, I am romantic with both of them. They each know I am with the other, and, while my girlfriend is still working on her jealousy, she can interact with my boyfriend in a way that is casual and friendly, without any repressed anger.
Do you have any specific questions you want to ask? That might make explaining easier.))