Knock at the back door

Well Marissa didn't slap you away when you touched her there. you pull out of her pussy, and don't give her time to think as you enter her from the rear. She lets out a gasp at the pain and grits her teeth as the sensation mixes with Britney dutifully lapping at her clitoris.

You keep pumping, as you get closer to climax you grab Marissa's hair and pull her mouth back off of your friends wet sex. The feeling inside you builds and builds until you release. You feel Marissa tense and squeeze her eyes shut. The feeling of being filled with your thick seed triggering her own orgasm. You pull out, leaving her panting and for a moment you're not sure how she will react to your...improvisation.