General Discussion
In reply to the discussion: Apparently, some people got their panties in a bunch over the multi-lingual Coke Commercial [View all]"Panties" was first a condescending way of referring to men's pants. If you were a real man you wore pants; if you were acting immature or effeminate, you wore "little pants" or "panties."
The word spread to "bloomers" later.
The "panties in a bunch" is the American (via Australian English) variant of "knickers in a twist." Which surfaces first in the very early 1970s, and is apparently from a British tv show from the late '60s. Given how scurrilous British humor could be ...
In any event, within a year of its being coined it was used unisex. Might have been unisex from the get-go. I'm more likely to say it to a guy.
I tried to find out if it's related to "don't get your nappy in a knot"--which has to date to at least 1972 or '73 but can't find squat. The meanings line up, and "knickers in a twist" might be a grown-up variant of "nappy in a knot". Or maybe the "knickers" line was made more condescending by implying the other person was a baby.