Could the peridise accidentally slide in all the way?

No need to push. It is no meant to go all in (because it moves less then).

It can, though, and I don't see any danger.

I worried about this also when I first got my peridise set. They never have gone all the way in after many uses. I think it would be kinda hard for that to happen as your rectum muscles want to squeeze around it while the two flared ends keep it from slipping in. I guess it might be possible if your stretching your hole open constantly but still not likely.

There was a guy here some time ago who said that his Peridise had slipped in all the way. I asked how he had extracted it but I got no reply. Perhaps he's still trying.

I had one go inside so that just half the tab was showing but never all the way.

If you are concerned why not tie a short string around the tab neck.

I don't think there's any danger of a Peridise going in because the base is just too tapered and flared. It's kind of pointy there also. If you even tried to push it in, it would catch at the base and no doubt hurt.

The tempo is another story. I use mine for hours and have never even come close to having it disappear, but its base is much more gradual.

Also, to clarify both points: I am like a crazy person who fears an Emergency Room visit. I never sleep with anything in except occasionally something with a P-tab.

Sometimes, when I run a late night session, finish, and put toy away, I wake up anyway like 2 hours later in a cold sweat wondering: "Oh my God! Where is it? Did it get sucked in". and it takes me a second to remember I'm fine.

That's how crazy I am. Wonder if I'm the only one with this phobia. . .

I think I will just put a little string around it just to be safe.

Btw, has anyone of you tried pressing a flat vibrator against the base of the peridise when it's in?
This way it's almost like a peridise with inbuilt vibration. I think it feels pretty good but I don't know if the vibrations interfere with the body's quivering response.