Fuck Katherine as she fucks her sister

You drag Katherine over to her sister and bring her up to her knees. Her hands are still tied behind her back so you have to help her balance. You pour lube all over the dildo and then pour some more on Sabrina's ass again.

"I'm going to guide you to your sister's opening, and then you are going to push in and start fucking her with the dildo around your waist. Got it?" you tell Katherine. She nods silently.

You position Katherine behind Sabrina and push her forward. The dildo pushes against Sabrina's asshole, straining to break in. You push Katherine harder, getting behind. Still the dildo can't seem to push in. You reach around the side of Katherine with both hands to grab Sabrina's hips. She tries to squirm away, but your grasp is firm and you yank her backwards with all your strength. The dildo suddenly enters Sabrina's ass, driving almost halfway in and Sabrina screams in pain, trying to get off. You'd don't let her and pull her back even harder. A bit more of the dildo slides in, but its still not more than halfway in.

"Its in, now start fucking her with her," you tell Katherine. Katherine starts trying to move her hips forward and backwards, although the dildo is jammed in so tight, that she's really just pushing and pulling Sabrina against the cushions underneath, the strap-on not actually moving.

You want to fuck Katherine and the best position you can think of is reverse cowgirl. You **** Katherine's legs open and then lie down behind her, You slide underneath Katherine so that you legs are in between her's but to the side of Sabrina's, allowing Katherine to continue the anal fucking.

You position your cock below Katherine's opening, and then place your hands on her hips. You pull her downwards, and your cock begins to enter her. She's surprisingly wet and ready, although you still have difficulty getting all the way inside.

She feels like heaven, and the sight of your cock entering Katherine's teenage pussy at the same time Katherine's strap-on is buried inside her sister's ass is surreal. The naughtiness, the dirtiness, the endless opportunities ahead for even more...

You bounce Katherine up and down on your cock, slapping her ass while you're at it. Katherine continues trying to fuck her crying sister, although the dildo remains wedged in Sabrina's ass so tightly it barely moves.

You're soon on the verge of orgasm and you grab Katherine and pull her all the way down onto your cock. She yelps as you bury yourself to the hilt and then start emptying your balls into her. Stream after stream shoots into Katherine. You collapse back onto the floor as you finish, pulling Katherine backwards with you, causing the strap-on dildo to bend and then flip out of Sabrina's ass. All three of you lie there, Sabrina still gasping and crying in pain, Katherine silent but shaking and you enjoying the bliss of one of the strongest orgasms you've ever had.