Having been married for 31 years, my first anal was after the marriage ended, at the age of 52 (2007).
I was visiting Melbourne, and went to RAM lounge above an adult video store. A few guys were there. I started playing with a lovely Asian man (nice dick). He suggested we go into the private room. There were undressed and started enjoying each others' naked bodies. He said he would like to fuck me. I took a deep breath and thought, "Here goes! He's not too big, this will be my chance. I let him know that this was my first time, and he was very respectful. I got on all fours and he (having lubed my tight hole) began to press his knob into my hole. I wasn't sure it was going to go in, but he gently persisted. As he broke through the first barrier I thought I wasn't going to be able to go through with it, but he eased in gently, and eventually was rhythmically pounding me. After a while he said I want you to turn over so I can cum. So I lay on my back on the bunk, while he stood between my legs. He lifted my legs over his shoulders and again began thrusting his dick into my now quite receptive hole.As he got closer, he started speeding up, then pulled out, tore off his condom, and let his load fly.
It was a magical evening. When I went back out onto the street, I felt like I was floating, and my mind was filled with dream-like sensations. Since then, my best fucks have been from Asian guys - partly because they are generally a bit smaller, and partly because they seem to be particularly sensitive and sensual lovers.