Anal!!

Ashley
I want to try anal with my boyfriend and he is big so that worries me and I'm scared to shit on him. I have told him I am scared to poop on him but he still doesn't want to wear a condum but will use lots of lube to make it less painful! I'm scared it's really going to hurt.. Can someone give me advice on what to do to make it less painful positions? Lube? Shower? Does poop get on him? Do I get an enema? How does that work? I've gotten anal once but this guy stuck it in the wrong hole and it went in there and didn't hurt at all but he was way smaller than my boyfriend now. Anyways help anyone