2T4U/Jack/nature trail/“fort”/Poke her cheek with your dick
She is so oblivious, lost completely in her fingers and what they are doing between her legs. This is just too tempting. You've got to have a little fun with her. Since she is already shamelessly frigging herself outside, you figure what you are doing is not crossing the line TOO much.
Trying to suppress your mirth so it doesn't come out as a giggle, you quietly close the last 1 foot of distance. Now she is so close you are afraid one wrong step will cause you to bump into her. However, with all the sports you have played, you are easily able to time the movements such that you can go in for the precision strike. You hold still at the ready for a moment, and then when the timing seems right you thrust your hips forward and press your dick hard into her cheek.
To your amazement, she hardly budges or misses a stroke. She doesn't even seem to realize what is touching her. She merely tries to brush the side of her face with her shoulder, trapping your dick against her cheek. In the next motion, she lets up with the shoulder and then a hand flies up to grab the offending object and suddenly you have her dainty little fingers wrapped around your meat.
It is only just now she seems to realize she is not alone. Her body stiffens as she turns around to look up at you, but her hand never moves from your still very hard cock. Suddenly, a grin spreads across her face. A familiar grin you feel you have seen in SO many lust-crazed girls before you fill their little pussies full of sperm, but there is something unsettling about this one. She turns her hips toward you and spreads her legs wide, then begins pulling down on your cock as though to guide you.
Go ahead and let her guide you into fucking her
Drop to your knees, but don't let her insert you just yet