That's also if it's not a Poly or ENM relationship.

Shits tricky these days. I have 3 partners, one trans-man, two women.

I'm not actively dating at the moment, but when I am, I always start out saying that I'm poly with X partners. Never blindside somebody like OP was.

I feel for OP. This was most definitely NOT their fuck up. It was the other guy all the way.