They were not just simply friend
It started from a flirt/hookup and end up with a relationship… They split because of their non compatible lifestyles and Thiem’s intense schedule around the world. Thiem’s was to much focus on his preparation, because of his career priorities, it’s high discipline & daily devotion…
Press were aware of this, as well as a lot of people. Tennis and tournaments world is a small, it’s not because medias don’t talk about this that they didn’t know ahah. It’s not like soccer, they don’t care about players private life.
They never have hide their love, it was just about respect and privacy. If you check old Kostas and Dominic posts, you should find their respective comments almost everyday (even Thiem’s brother Moritz was responding with heart or emojis like )