My wife is horny, and since it's Friday, we are going to wash the week away with some hot shower sex. I'm going to have some lube ready, and when I'm hitting her from behind, I'm going to finger her ass. Then I'm going to lube up my cock and rub it over her hole, putting a little pressure on it, but not enough to go penetrate. Then, if she wants it, I'm stretching open her hole to give her the tip of my lubed cock. If it goes well, I'll kinda vibrate for a few minutes so she can used to that new sensation. Maybe I'll give her a little thrust or two. Then I'll slowly pull out of her ass, and resume banging her tight pussy.
If we don't do the butt stuff I'm still going to fuck her senseless. I'm honestly good either way.