I love how she pushes it in him... It's tight with his anal sphincter giving her some resistance at his hole's opening, but once she gets it past that, it pops right in there, and she can give him a good hard ass fucking...and she really does. He's totally at her service, and she takes full advantage of him, the obvious slut he is.
Did you ever get a fatter dildo to use with your strap on harness on your husband? You mentioned you would...I think something like this would work well... Not as long, but much fatter, allowing a better stretching of his hole, and a good, hard pounding.