anal confessions

alright so me and my boyfriend have been wanting to try new things to pleasure each other so we both deicded on anal. Well it was going good and he had a condom on and all of a sudden i felt this weird sensation and he stopped and he had poo all over his dick and i just felt so horrible and embarrassed but i didn't even have the urge to go before so i don't know what happen ?? does anyone else have any similar experiences or advice?!☹️