In many relationships, partners may realize that regardless of whether they respond or not, they believe that there will be negative consequences. In my practice, I see it rather regularly. Zugzwang is a term adapted from Chess, where either move leads to a worse outcome than doing nothing. I often hear of partners standing silent as their spouse demands that they just say something. This is relational Zugzwang.
When couples become stuck, it is often due to poor communication. Poor communication is partially rooted in having some hope that communication would improve the situation. When one partner believes that communication will make things worse, they sometimes get stuck in something called zugzwang. It’s very closely related to the Gottman concept of stonewalling, which is one of the four horsemen of divorce.
To un-zugzwang, you both would have to have the conversation about it, which includes communication, the one thing that they are avoiding. I have found that there is an intimacy expectation to speaking, which often results in boundaries being broken. I have found that it is much more tolerable to an Aspie partner to write out their thoughts and feelings at their own pace, rather than in real time. It leads to a more thoughtful, compassionate exchange of ideas. It rarely leads to yelling or name calling. It is much more difficult to say horrible things to our partner on a sheet of paper. There is more respect and many opportunities to rewrite your thoughts as well.