FML anal accident

So the other night my boyfriend and I decided to do anal. It was in the heat of the moment (and also vaginal penetration was doing nothing for me) so I didnt have time to prep, i.e. use an enema. So he has a condom on and starts going at it. I'm having the time of my life and he suddenly stops and just stays silent. Apparently I shit on him. I was so caught up in the thrill of anal I hadn't realized it. Has this happened to anyone else? I cannot be the only one out there, y'all. Oh yeah and since then he hasn't really wanted to have sex which is totally understandable but also makes me feel all shitty and embarrassed. What should I do?