Having interests in another person could apply to a few different situations. Someone could take a romantic interest in another which would mean they were interested in pursuing a relationship with that person. Someone could also have interests in regards to someone meaning they are curious about who they are or they would like to learn about something someone has done. Either situation would be considered a general interest in the other person.
What that person likes to do on their free time.
If you have a fiduciary obligation to act in the best interests of another person, and with intent, you act against that person and in favor your own interest, you have committed a criminal breach of trust.
If you mean "behalf" as in "the interests of a person, group or principle" - some other words could be: sake, stead, benefit, advantage... I don't know if that was what you were looking for, though...
Kids rarely share parents interests either. it depends what kind of person you are and what interests you. Just because your dad is into fishing doesn't mean you have to be. They are interested in YOU but not necessarily your hobby.
It is when you are mean to another person and you get in trouble.
it means you or another person!
The term "when one person surpasses another" means that one person has overtaken another. It also means that one person does something better than another.
Dreams
they say it means the person who did it likes the person they pinched
Person versus person refers to a conflict or competition between two or more individuals. It can involve disagreements, arguments, or physical confrontations as individuals assert their interests or beliefs against one another.
A person who learns a job from another person.
To conceal the truth.