It's your birthday morning. Your wife is upstairs while your SisterInLaw follows you downstairs with a very special gift. My hand slides over your hard cock through your pajamas, cleavage on full display. You're nervous, guilty, but you follow me to the guest room anyway.
You stroke yourself while watching me strip naked. Then my mouth is on you, shushing your protests, promising nobody will ever know. The walls are paper thin as you let me mount your married cock and ride you raw. You try to stay quiet while betraying your wife, the guilt only making you harder.
You beg me not to cum inside - you couldn't live with the betrayal - but a dirty cheating husband doesn't get a say. You try to pull out at the last second but I'm not letting you escape. You explode deep inside me, filling me with your seed while your wife is in bed next door. No birth control. No excuses. You belong to me now, for however long it takes to get pregnant.
