Like others have said, relax (liquor helps) and lots of lube are a must. But, the biggest key to enjoying anal sex is to have a lot of stimulation in other areas. This takes your mind off of what you don't enjoy, until you start to enjoy it. Since your man will be busy doing his own thing, I suggest you do it yourself. Get a really good toy and stimulate your clit and/or pussy with it. My suggestion... a good vibrating egg (or two). This trick really works, trust me. I enjoy anal a lot more now. I shared this trick with a friend's girlfriend and he now thanks me because she begs for anal sex all the time. Let me know how it goes!!