That's probably the smart thing.

With me and Crystal still both burning with passion to be fucking some more, I slipped my cock out of her slick pussy and started to stand up.

My hand immediately went to my cock, as I was too close to not finish now. Similarly, Crystal sat back onto her knees and her hands both flew to her pussy, where she vigorously rubbed her clit with the middle finger of one hand and massaged her outer lips with the other. Her arms pushed her tits together and as she gyrated, riding her fingers, her chest heaved over and over again; all the while my balls quivered, threatening to cum any second. As she looked in longing wonder at my massive cock being jerked off, she quickly fingered herself into an orgasm. Scrunching up her eyes, Crystal let out a string of long, high-pitched moans. With my free hand I reached out and grabbed a nipple, squeezing it gently. The moans got higher. Finally my balls emptied, and I sprayed rope after rope of semen onto Crystal's heaving chest, streaking her enormous titties with my cum.

She collapsed onto the carpet floor, breathing heavily, her fingers still slowly massaging her relieved pussy. I lay beside her, also out of breath, my cock dripping with the remnants of my barrage of cum.