decide to jerk off to her as you walk

you cant stand this anymore and to looks of her wiggling ass in her leggings you put you hands down in your sweatpants and start caressing your dickhead. she drops her phone on the walkway and with stretched legs she bends over to pick it up exposing her big as ass. it tickles in your dick as you see it and you can feel climax is close. you walk closer to her. you stumble on a rock with the girl hears, and she turns arounds. you do the same. she sees you ofcourse, but you are not sure if she saw you jerking your dick inside the sweatpants. luckly you hear her walking again. you turn around and see her putting in some earphones. you walk up to her almost as close as you can pull out your cock and burst a big load onto her ass. she do not feel it. and you run in the opisite direction hiding behind a wall. as you look out you can see from far away she notice she has something on her ass, put luckly she will never know what it was, or where it came from.