Niece coming out of the shower

My niece and I were hanging out on the patio getting some sun and having a few beers. In upstate ny there are a lot of bugs in the summer so we sprayed down pretty good with bug spray, after a while you just feel grimy and need a shower. So I went in and rinsed of while my niece waiting. I came out with a towel around me to find her waiting with a towel around her. I told her it was her turn and she went in. I pretended to get changed and leave the room. Instead I stayed on the edge of the bed. When she came out her towel was barely covering her, my cock got instantly hard, which wasn't too much of a stretch as I was already horny. She stood there for a moment and I just stared at her. I told her how great she looked, she said thank you and walked over to hug me. I know when she pressed her tight fit body against me my cock grew even more, and I know she could feel it, I held her and rubbed her back, i wanted that towel to drop to the floor. I would've rubbed my cock all over her young pussy, and came all over her