Just tried anal

Faith • If you have a question, just ask. It's better to know than be ignorant

So me and my bf have been wanting to try anal for a while, and we finally did it today. Well, tried to. He used plenty of lube, and i was pretty relaxed. He did get it in all the way, but I couldn't let him stay because of the pain. But we did slowly ease into it and got quite a bit of him in where he could thrust, but I just want to know advice for getting anal to work a little smoother, and maybe how to avoid the worst of the pain.