It's wrong to not make your intentions clear when dating.
Jimmy has been seeing a girl recently but met a new girl that he likes more.
Jimmy wants to date the new girl.
Jimmy explains to his current girlfriend that he thinks they should break up before he asks the new girl out.
Jimmy starts dating both girls at the same time without telling either of them about the other.
Jimmy's current girlfriend is upset at first but is able to move on and eventually stay friends with Jimmy.
Both girls find out that Jimmy is cheating on them, and they both break up with him and never speak to him again.