It means that you slowly become bored with your partner.
But I love it.
There is chemistry between them and they start going out with each other so they start becoming boyfriend and girlfriend, and then, maybe the fall for each other And then, eventually, perhaps, who knows, they get engaged and get married and have children and live a lovely happy life.
Description: This means that the relationship finished. Okay, in English, there are numbers of expressions that we always use when we are talking about romantic relationships, boyfriends, girlfriends, and going on a date.