Mostly right. I’ve done extensive research myself and found no evidence of the butt plug breaking when someone was wearing it. Two things are most likely to happen. One is that the stem will break eventually, because that’s one of the smaller, more stressed areas in the glass, and the more you use the plug, the more stress it gets. Another is that gradual wear and tear can cause cracks or chips to appear on the surface of the plug. You should always inspect your plug thoroughly before and after use, and if you notice any of these damaged areas, stop using it immediately and buy a new one. Definitely not worth scratching the inside of your rectum just to save some money!