My interpretation of Vivarium

To me, the most prominent theme in the movie was "The Cruel Hell of Parenthood" ™️.

Martin brings up kids as soon as Tom and Gemma arrive at Yonder. Even though we see them get trapped there some time before the "boy" arrives, the movie goes the extra mile to make it clear that raising the boy is the only way to be released, lending weight to the idea that the boy is the main reason for their captive, inescapable situation. All their attempts to leave Yonder, burn down their house etc can be seen as failed attempts to stop/terminate the pregnancy.

Other themes that are often taboo to discuss with regards to parenthood, are also depicted very vividly.

For instance, the boy destroys any concept of intimacy or privacy between his "parents". Their entire life revolves around providing for him. They have no joy. Nothing else to do, or to talk about. Even their beautiful, brief dance in that glum dystopia was interrupted by the parasitic spawn.

The wedge he drives between them ultimately rips them apart, and keeps them so until it's much too late to do anything about it. Despite the fact that the boy is clearly not human, and is responsible for their unending misery, Gemma starts acting more and more like its mother. It finally comes to a head when she refuses to let Tom try to starve it, not even to save themselves.

It's possible, even probable, that it would not have worked. But she didn't even let them try it. Her sense of responsibility towards the creature outgrew that of hers towards her partner. And this, broke Tom's spirit.

For the first time, he was alone. In every way that mattered. He no longer had his partner. They were not a team anymore, nor each other's priority. He stopped fighting, and surrendered. This is also when we first see him starting to get sick.

I read a great piece of writing some time ago, called "Being a husband is lonely", don't remember where exactly. The main idea was that once kids are in the picture, dads/husbands are no longer the most important people in anyone's life, which can be very isolating. Another one of those things that many people may see and feel, but don't like talking about.

Overall, a very good movie. It scared me and made me think, can't ask for much more.