First, there is the event that happened (or something you are thinking will happen) which then triggers some thoughts which then feed your consequent behavior.
It’s ABC.

A. There is the ACTIVITATING EVENT
B. which activates your BELIEFS AND EMOTIONS about the event
C. which then activates some CONSEQUENCE such as your feelings and/or consequent behaviors.

For example,
Your spouse said, “We are going to hit traffic”. A pretty neutral comment. (A. the activating event)

You made an assumption that they were complaining about you not being late and it triggered a thought process that my spouse doesn’t understand how much work it takes to get out of the house. (B. your beliefs and emotions)

Then, you get all grumpy. (C. the consequence)