you can't participate in this

"i'm sorry but i won't participate in whichever horror you've planned!"
she smiles "it's a bit late for that, isn't it?"
then they half untie you and between the three of them they turn you around and change your possition for getting you on the four
"this won't be useful but funny for the guys"
then your own son gets down his pants and roughly interoduces his cock in your ass
you scream badly in pain as he does it, feeling your tight ass getting forcely opened
he fucks you hard and you can notice he's making you produce some cum as if you were having an orgasm but without the pleasure on it
after a while when you thought you were getting used and it hurts less bad he stps and cums inside you
"congratulations, from now on you're the free use anal sex toy for everyone to use... i guess the guys will use you lots" Allison says with a smile at the time your son nods "i sure will"