Hi, Thania!

So, the word "Uncle" was capitalized?  If so, this would mean that "Uncle" is a person, a character in the series.  In that case, "to play Uncle" could mean "to deceive, manipulate, etc."

Don't play me like a fool. = Don't lie to me, cheat me, fool me, deceive me, etc.

Does that make sense?

--  Dale

PS:  By the way, as kids we used to wrestle with our friends, often telling them "Say uncle!"  If they replied, "Uncle", we let them go.  So, in the expression "to say uncle", sometimes people literally say it!