I don't get it are the parents breaking up?
@Zei
They aren’t breaking up. Some humans never get a connection with a fated person. And they live sometimes happily with each other. It’s explained in the second volume.
It was just MC’s bad luck, that he ended up with people who later in their relationship connected through fate with other people.
That’s why it makes MC happy to see the parents, because it is proof, that long lasting healthy relationships are possible without a fated connection.
Their strings most probably didn’t get cut like some other commenter suggested. They never connected with anyone.