"Oh, God!" Lynn moaned, knowing she couldn't talk Tony out of it. Her body trembled, the cheeks of her ass tightening involuntarily.

"I've got the knife," Billy said. "Take your hands out of her panties. I don't wanna cut you by accident."

Lynn felt the knife sawing at her panties, then they fell to the floor between her spread legs. She was naked from the waist down, and her face was flaming with shame as they looked her firm ass over.

"That gives me a fucking hard-on," Billy said. "Hey, Lynn, you ever let Dad assfuck you?" He giggled lewdly. "I bet you really go for a cock up your pretty ass, don't you?"

Lynn could not reply, her throat was constricted and dry. She felt their hands caressing her naked ass. Her body twitched spastically, jerking, as she tried to pull away from them.

"Wanna see her asshole, Tony?"

"Yeah, let's take a look at her asshole," Tony said. "I heard you can tell if a girl takes it up the ass by looking at her asshole."

"Yeah, I heard that, too."

Lynn felt the cheeks of her ass being parted, and she clenched them tightly, but it did no good. Tony pulled one asscheek and his brother the other. They exposed her asshole, squatting behind her and peering at it.

"Still looks tight to me," Billy said.

"See if you can stick your finger in her ass, Billy."

"Please, don't!" Lynn groaned, her asshole becoming very tight against the invasion. "I've never… never done anything like that before. It's horrible… shameful! Please, don't do this to me!"

"Shut your fucking mouth, Lynn!" Billy growled as he started poking his finger against her asshole.

Feeling the pressure against her asshole, Lynn held her breath, steeling herself for the expectant pain when he shoved his finger into her ass. The pressure grew as Billy pressed the tip of his finger harder.