to curry favor by acting obedient or showing off one's good behavior; to toady to

to pretend to be the victim or act like a good person despite having already gained a significant advantage at someone else's expense

To pretend to be at a disadvantage or act humble even though one has already gained an advantage; to have benefited from something but behave as if one has been wronged.

To act like a spoiled child and show off one's cleverness in order to gain favor.