Sounds like he don't want to hear what you have to say. :0(
That is pretty heartless if it happens all of the time.
Why does my boyfriend like to curve arguments? Whenever we fight he cuts me off in mid sentence saying "thank you for understanding babe"
He does it .. Because you allow it.
Kick him to the curb.....then tell him "thanks for understanding"
Because he likes to manipulate you. I can guarantee you if someone cut me off mid-sentence and said "Thank you for understanding", I would make it very clear that I am not understanding, and he better understand that if he cuts me off again without listening to what I have to say he won't get the chance to do it again because I will be gone.
You need to stand up for yourself, or he will keep walking over you.