This is how feelings get hurt. Ah, the good old "not technically cheating". You don't just meet someone and automatically become their significant other. You can address your control and other issues in therapy as well. Yes it's the default. It's representative of real life and it's also very logical. It just so happened that I was involved with 2 other people when SO and I met, but that honestly wasn't common for me.
Am I now in an exclusive relationship?
What does non exclusive dating mean
I will date, but they seem to know by the way I hold myself around other girls that I am non-exclusive. That decision is up to that person. As a hardcore monogamist I'd feel really funny dating two women at the same time and even giving both of them good night kisses, let alone doing more intimate things than that. I have a tendency to develop very intense monogamous relationships quickly, and to test my partners' commitment constantly. You have to decide what is best for you and act accordingly.