Author's note: This story is categorised as 'reluctance' rather than 'non-consent'.
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They'd been messing about for about one hour, since he'd gotten there.
He was ten years older, she loved to be chucked around, manhandled, shown her place.
He took a break to go downstairs.
Her mother, Lisa's mother, Polly, was down there, trying to pretend she couldn't hear them upstairs.
Polly was already more or less taken with him; its not like he ever pretended to be faithful to Lisa, or monogamous.
This evening he was feeling mischievous.
He pushed her further than even he was expecting. Before she knew it Polly was backed up against a wall in the kitchen, gasping, his finger hooked to the first knuckle in her cunt, under the band on her trousers.
When she got weak at the knees he drew back. He told her to undress, which she did, awkwardly.
When she had he didn't touch her, but looked her up and down, and told her to wait a few minutes --- just like that --- then to come upstairs and join him and Lisa.
She looked terrified, said she couldn't.
"You think someone like me finds one girl enough? The both of you, or neither, I'll leave Lisa and won't come back. Your choice."
He left her staring, and went back up.
Five minutes later he was on the edge of the bed, Lisa kneeling in front of him bobbing her head up and down and down.
She pulled her head back, "Come on my tits please."
"Why?"
"It turns me on, thinking you like my tits. I know they're small, so I love it when you want to come on them."
She went back to sucking for a while; "You can fuck me after. I'll suck you till you're hard again. Then you can fuck me however you want."
In the crack of the door-frame he could see the outline of Polly, watching.
"What if your mum heard you? What if she walked in on you begging me to come on your little tits and fuck you?"
He had his hand on her neck, forcing her deeper and faster.
"What do you think she'd do then, hmm?" he pulled her up.
She gasped air, said, "Maybe she'd join in. Maybe she's just as much a slut as me."
They'd talked about Polly a few times. He guessed Lisa would either do anything to please him, or she got off on the taboo. She probably hadn't known which herself, to start with, but now it was definitely both.
She went on, pausing every now and again to bob up and down on his cock for a bit,
"Maybe she'd get down here and suck your cock with me...
"We could suck you off together...
"You could come over the both of us, we could push our tits together and you could aim between us...
"Then you could lay me me back on the bed; and lie her on top of me so I'm pinned down...