She was using him for her own sexual gratification. Note how her heals were locked around his legs so he couldn't escape. I counted at least six minor orgasms before she had a massive one between 4:30 - 4:50. I'll wager she slept like a fucked rabbit after that workout.
Beautiful scene with two sexy people. I'd love to be there paying tribute to your wife's gorgeous ass with my tongue! Thanks for sharing your sexy game.