This is a work of fiction. All characters are over eighteen years of age.
"Daddy, why are we hiding in the bushes?" asked Tabby.
"To see what your mom's really been up to all this time," her Daddy said.
They were crouching in the darkness outside the home of Daddy's sister-in-law. They'd parked two blocks away and were creeping like burglars through her suburban backyard. Their objective was the brightly lit window ahead of them, showing the home's master bedroom.
He'd brought his eighteen-year-old daughter Tabby with just in case his suspicions were correct. The two of them were having a torrid incestuous relationship that had just escalated into their first threesome, with Tabby's best friend May. He'd been training his Tabitha to be his fucktoy and it was going better than he could have imagined.
Bob King thought his wife was cheating on him. He wasn't sure with who, or if she really was or not, but after finding some unexplained lingerie in his guestroom he'd formed a sneaking suspicion he wanted to check out. His wife Heidi had been spending a lot of time 'at her sister's house', his first step was to see if she was indeed where she said she was.
To his initial relief he saw his wife's car was in the driveway. Seeing that he'd been tempted to take Tabby and just go back home, but he needed to know for sure. They circled into the backyard and were now approaching their target. The shades were pulled but there was a gap of a few inches near the bottom, and the window had been opened a crack for the breeze.
Daddy held his finger to his lips for silence and they crept closer and closer. Faint cries were coming from inside. Tabby listened, gasped softly and gave her Daddy a big smile. Daddy returned it with a thumbs up. They settled at the window's base and peeked in.
On the big four-post bed, Tabby's mom Heidi was being orally serviced by a woman who Daddy recognized as her sister. Heidi was moaning and grabbing her tits, she was about to climax.
Tabby was stunned. Her own mom, and her aunt Dixie, were lesbians! She watched them going at it, the slurping sounds and her mother's cries were getting her randy. Then Daddy took her hand and placed it on his bulge, he was turned on too. He unzipped quietly and Tabby took his cock out.