Hi Crysti and Adam,
Welcome to our forum.
It sounds like you have been on a journey of sorts for some time, definitely not static or stagnant. It's definitely okay to seek a triad relationship; I'm surprised (and bummed) about the negative reaction you received in that area.
Are you okay with being secondary partners to the person you're currently with? Would that fit with the triad set-up that you had envisioned?
Glad to have you aboard.
Love means never having to say, "Put down that meat cleaver!"