Evening in the house — this is a kind of greeting that is often used in informal situations, especially among young people or in certain communities. It's something like Hello everyone! or Good evening!. This greeting originated from the prison environment, where evening in the house means wishing a peaceful evening to everyone present.
When you hear evening in the house, the response can vary, but most often people say morning in the house or good evening. This is a kind of continuation of the greeting that maintains a friendly atmosphere. Some may get confused about whether to say evening or eve, but in the Ukrainian language, of course, it's better to use evening.
Sometimes you can hear variations like evenings or evening, but that depends on regional features or personal preferences. The main thing is not so much correctness as sincerity and friendliness in communication. So, if someone says to you evening in the house, don't hesitate to respond with a smile!