The second hottest thing in the world is fucking a married woman bareback right in front of her husband, making her moan uncontrollably like a horny slut as you orgasm together, knowing her husband is hearing her make noises with you that he's never heard before.
The hottest thing in the world is when you're the husband, and it's your wife getting used, knowing that she's so into it that she's only barely aware that you're there and doesn't care because the center of her world is the cock thrusting into her.