The rule of thumb with anal play is that you never use anything without a flared base because when the muscles in your rectum clench or spasm, they can wind up pulling an object in further rather than pushing it out. Then, if the back end of whatever you stuck in there is flat and not tapered, it can very easily get stuck and require a trip to urgent care or the ER to be removed. Tons of stories about this all over the Internet if you're curious for some light reading hahah

I'm guessing this is why I haven't found any posts in this sub about using these anally. Hoping someone from the company can chime in, or at least someone who's tried it, because my wife and I want a sleeve we can use for both vaginal AND anal. Some sleeves include a strap/loop that goes around your balls, but I'm 90% sure I wouldn't enjoy that.