In my dating life, there tends to be an assumption of a casual nature, less commitment at the beginning of a new relationship. As the relationship progresses, the man and I decide to be monogamous with each other ("boyfriend/girlfriend"). And that goes on until we progress to engagement (happened to me once) or we break up.

I've never been in a non-monog relationship so I'm wondering how long term commitment works for these types of situations.

I imagine poly people leave their partners often for some other partner that they just liked better. Is this an incorrect assumption? Isn't there a fear from the start of an ENM relationship that this can be very likely to happen?

I am just exploring this world, and I bought a couple books to read so I am trying to learn.

Thanks for your thoughts.