Her first time seeing me do it

The area around us is pretty remote and sparsely inhabited, so we are always the only people at certain beaches. I took my daughter and younger step-daughters to the beach, and while the younger girls played in the woods a ways off, my daughter went to the edge of the water, maybe 20 feet away. She walked aimlessly back and forth, and I grew hard as I admired her body. I was in the shadow of some overhanging trees, and figured she couldn’t see, or at least make out, what I was doing when I lowered my waistband and began fantasizing about her. She looked my way, but I assumed she didn’t even see me, because although she kept looking, she didn’t look away or show any reaction that I could tell, but after taking just a few steps she was upon me, pathetically fumbling to hide my erection as she asked “What are you doing?” “Nothing, I just, you…” Even as the words came out of my mouth I knew it was pointless, and I realized she didn’t seem upset at all. I was still fumbling with my words, embarrassed but still hard and even hornier from the thrill, the forbidden nature of what I did, the danger and the even more taboo thing I was about to do. I hadn’t even gotten my dick back in my pants, so as I said “You know.” I began stroking, looking down at her breasts. I put my hand on her shoulder and left no question as to what I wanted her to do. She knelt before me, her mouth inches from me. Twisting her long hair around my fist, I pulled her head back, her mouth opened naturally and her eyes found mine. Nervous, scared and shaking, she must have known that I wanted to use her mouth deeply. I became aware that her step-sisters had been calling us from the car, bored and anxious to get home. I was so close to cumming, and her breasts were so inviting that I let loose into the cleavage between them, then used my cum as lubricant to squeeze between them, sliding in and out, milking the last drops. She was used, I used her and I wanted her to know it, so I made her walk back to the car with my cum splattered over the tops of her breasts, dripping between them, down her stomach onto her bottoms. I let her put on the shorts she had been wearing when we stopped to get ice cream, getting hard again when I insisted she come to the window and order with us.