I was 47 when I first had anal sex and t be honest it wasn't something I'd thought about much before.
After my divorce I met a new woman who was up for anything. We'd started to have a little anal play and she loved having her asshole fingered and tongued. Still does as you can see from the photo. 10 years on and we're married.
One day when she was on top she reached round and eased me up her ass then she leaned back so I could see my cock going in and out of her ass while seeing her pussy.
Don't know why, but coming in an asshole just seems more pleasurable
An afterthought - one day after we'd had anal I was in the barbers having a haircut and I got a text message. It was from her saying that she could still feel my cum leaking out of her ass.