Looks like you are in the perfect position to get a good view of her sitting down on his lap waiting for you to line up his cock so that her ass can settle down on it
Have experienced this. It's off the charts hot. This is how one of our first sharing experiences went, early in our marriage. He didn't want me in the room with them. Neither did she.
im sure she will take it like a big girl and enjoy it too. she is classy and gorgeous. her booty is a delight to the eye and heaven for any cock driling it.
she is assuming very well that nice big dick, she is having a mouth full and handling it with both hand. that a hot woman taking care of a hard dick and enjoying it.