Определение и Значение "[have] something going with {sb}"

What is the origin of the idiom "have something going on with someone" and when to use it?

The origin of the idiom "have something going with someone" is uncertain. It likely developed as a colloquial expression in English language over time to describe a romantic or intimate relationship between two individuals. It suggests that there is mutual interest, attraction, or a developing relationship between them. It can be used to describe various stages of a relationship, from initial dating to a more serious commitment. For example, "They have something going with each other" means they are romantically involved or exploring a potential relationship.