"These aren't my pants"
Apparently that answer never works.
No one ever "made" me, but, I'd probably say it's a medical device, or my PDA, (Personal Defense Assistant) if they asked about my SafePacker, but if I'm actually unconcealed accidentally, I'd say I'm legal to carry it. (Although where I live, probably everyone in the HEB with me is too, and would just whisper that my 2A was showing)