If they have moved on more quickly than you expected, don't judge them.
Maybe, it was what God planned for them.
Maybe God wanted to rescue them after all the wreckage you brought into their life.
It's not always about choosing someone else over you.
It's mostly about choosing to grow, choosing to heal, choosing to learn, choosing to set their priorities straight, choosing to save one's own self for the people who depend on them to survive.
Maybe moving on was not a choice.
Maybe moving on was not a choice but the only option they were left with.
We can linger on to it and make us miserable or get up, learn from it and move on.