I find it really hard to define and it changes over time. With my previous T and my current T, I felt a connection to them as soon as I met them and it deepened over time (and continues to deepen with my current T). I saw another T for a few weeks in between those two and never really did feel a connection (which is why I no longer see her).

There was just something about both of those Ts that made me trust them enough to talk to them from the start. Something in their eyes told me I was safe there.