"I am going to fuck you in the ass"

I say and stand up.

"Ha, you certainly are not going to do that." Millie says and starts laughing.

I walk up to Millie's sun lounger and grab her hand, pulling her up so she is sitting up, her face close to my cock. Millie gets a bit of an annoyed look on her face and says in an irritated tone:

"Matt, leave me be."

I don't respond, instead grabbing her shoulder with my other hand, turning her around and pushing her back down on the sun lounger, face down.

"Matt!" Millie screams, a sense of panic now in her voice.

I straddle my step-mom, my hands pushing down on her shoulders, her face pressed against the sun lounger.

"Matt!" Millie again screams, as I pull down her bikini bottoms with one hand, the other pushing her down on the sun lounger. I get my step-mom's bikini bottoms down to her knees, then I reach for my cock and start pushing it against her ass cheeks.

"Matt! No!" Millie screams, trying to clench her ass cheeks shut.

This proves of no use, as my cock is already between her ass cheeks, probing. I keep moving my dick up and down, then thrusting forwards, trying to get it into Millie's ass. Millie is squirming beneath me, trying her best to avoid this happening.

Then, finally, as I push my dick forwards, I feel it pushing into something that gives way. I hold still for a second, feeling Millie's body tense up, then she starts squirming violently, screaming loudly:

"Noooo!!!"

I push my dick deeper, feeling my step-mom's ass opening up to the intruder.