I want to describe a situation in which I acknowledge that someone has done something for me in the past and so I am grateful for it but the person upon hearing this exaggerates the importance of the favor and starts behaving as if I am obligated to him for a lifetime. Is there any idiom for this person's behavior?
Two related idioms come to mind:
"Lord it over" (M.W.), meaning to behave like a member of the aristocracy and assumes the right to be acknowledged superior: "He helped me in the past and now he just wants to lord it over me".
"Make a mountain out of a molehill" (M.W. 7) - to consider something of little importance to be something of great importance: "I acknowledged his help and he made a mountain out a molehill about it, claiming I owed him a life long debt of gratitude."
Although these cover the ideas of assumed superiority and exaggeration, I am not sure there is a single English idiom that matches the saying from your own language in its entirety.
In response to comment, the young Hindi saying could be translated as "I raised you up a hero and all you did was piss in my ear". It's vulgar, not something commonly expressed in English, but could work in film subtitles to translate Hindi dialogue which uses the expression.