A couple of years ago we used to live in a mid century building in a different part of the city. The building had 2 apartments on each level and a central staircase connecting 4 floors. We used to live on the top floor and Anna and her boyfriend on one of the lower floors.
Anna and her boyfriend were about the same age we are and after my wife and I ran into them a couple of times we exchanged phone numbers. After that the four of us met up a couple of times for drinks and board games and we texted away about rumours in our building. We exchanged keys to our houses so we could look after each others plants and pets during holidays, which somehow I always ended up doing.
During our meet there was always some tension between myself and Anna. We would get flirty and laugh out loud to each others jokes, it got so obvious my wife made several remarks on it. From time to time Anna and I got flirty over the app complementing one another about a piece of clothing or a shared article on social media.