1. To give someone a hard time.
2. To be a hard ass.
" I'm bustin' chops today. Ask anyone." ~ Janitor on Scrubs
to push someone to the limit of his abilities, especially someone's physical skill or prowess in his area of expertise; (probably originally musical slang)
You'll enjoy drumming for Karen, but you'd better keep up your practice -- the speed she wants during those long solos will bust your chops.
Working with platinum is bustin' my chops, I wish I could go back to working in silver.
Bustin' chops is his favorite thing to do on the midterm, so make sure you've memorized all the formulas.