Husbands wants anal but I’m uncomfortable

My husband wants to do anal, and we have done it before a handful of times. But I really don’t like it. It is uncomfortable and hurts and the last few times we did it got grossly messy at the end…if you know what I mean. He doesn’t seem to mind about the mess but I do.

I want to do this with him but I don’t know how to make it more comfortable for me. And I have a god awful time trying to relax before anal. My whole body tenses which doesn’t help.

Any suggestions help, sorry for the gross details.