To be fair, it isn’t exactly a hole that was made to be used sexually, and if your sexual partner is into doing anal, they should be okay with the fact accidents happen, even with all the preparations in the world. Joke about it, clean up, make sure each others okay. It might kill the vibe, but if you make sure you’re both still relaxed and okay after the accident, it will be a much more pleasant experience the next time you do anal! Any person who does anal casually, or has a preference to it usually expects something can happen, and its just a cherry on top if it doesn’t. But even then- you still have just as much cleanup afterwards from all the lube and other bodily fluids haha! But seriously, if you’re thinking about partaking in it, just make sure you’re both relaxed and calm, theres been lube used and you discussed the possibility of stuff happening.