Remember the little Colt .380 that looked like a scaled down 1911? Can't think of the name of it right now, but I had one many, many years ago. Even back then, I was doing the no holster thing. Somehow, the gun worked upward while I was driving, and when I got out of my car in the K Mart parking lot, it fell to the pavement. That was way back before cc permits were available (I was a rookie cop). People turned to gape as I fumbled around trying to pick it up and get it out of sight. I was too embarrassed to go in the store. So, yes, a gun tucked in the belt ain't the safest way, but it's convenient. I'm still doing it. Other than that once incident, I've never had a problem with my 1911 moving.
I think someone ought to start a thread about stupid/embarrassing moments they've had related to cc. I'd open such a thread myself, but I'm scared I'd be the only one posting. I've had a gun in my hands or within reach for more than 40 years, and I admit to a few blunders, but that's all I'll say until someone else 'fesses up.