In working with the male half of the couple, we dug down into why he wanted to avoid showing his anger, or upset with his girlfriend. It came to an irrational belief I've seen many times - that he is quite disposable, and if he causes any trouble, or doesn't make her happy, she will leave him.
I've seen this before (I remember it in myself). There is a great underestimation of not only his own worth, but of the strength of relationship. There is a missing of the truth that relationship can and does withstand conflict, disagreement, mistakes, and not always being "nice". At least a good relationship does. And to have a long-term relationship, you have to be able to have conflict. Otherwise, dishonesty and resentment simmer and bubble until you have REAL trouble.
That's the nugget for the day. My best to you.
Sincerely, Peter Hannah MA LMHC