Be a thorn in the side of, 3 letters
Bother the heck out of, 3 letters
Bug the hell out of, 3 letters
Do some button-pushing, so to speak, 3 letters
Drive to distraction, 3 letters
Drive up the wall, so to speak, 3 letters
Get on one's nerves, 3 letters
Get on the bad side of, 3 letters
Get on the nerves of, 3 letters
Get under one's skin, 3 letters
Get under the skin of, 3 letters
Go against the grain, 3 letters
It may be in front of some, 3 letters
Raise one's hackles, 3 letters
Ruffle the feathers of, 3 letters
Stick in one's craw, 3 letters
Test the patience of, 3 letters
Drove to distraction, 5 letters
Got on the nerves of, 5 letters
Got under (one's) skin, 5 letters
Hot under the collar, 5 letters
Rubbed the wrong way, 5 letters
What Leo the Lip did to umpires, often, 5 letters
Source of annoyance, perhaps, 5 letters
Going against the grain, 6 letters
Pissing off slightly, 6 letters
Drives to distraction, 4 letters
Gets on one's nerves, 4 letters
Gets on the nerves of, 4 letters
Gets on the wrong side of, 4 letters
Gets under one's skin, 4 letters
Gets under the skin of, 4 letters
Annoying IRS, obtaining check at last, initially overcharged me (7), 6 letters