As in The Sopranos, “I’m just breakin’ balls here.”, ie I’m not serious, I’m just having some fun with you. I think the first time I heard the expression was in Goodfellas, 1990. How old is the phrase? (I can’t find it in OED).

HDAS lumps it together with “bust (one’s) balls” (s.v. balls); the first cite is:

1944 in Atwell Private 53: In camp we bust our b—s learning how to climb over a mountain so they can’t see you.

First cite with “break”:

1955 Puzo Dark Arena 181 [ref. to 1940’s] You used to break my balls about it when we were GIs.

Maybe I’m just tone-deaf, but I have never heard an implication of having fun in this phrase.  To me it’s always meant causing serious problems.  “Yanking one’s chain” or “rattling one’’s cage” have the connotation of having fun with, but not “breaking (or busting) one’s balls.”