I'm gonna have to go for all of the above.
She jumps on you and starts tickling you all over, and then, from the physical contact and general pleasurability of the experience you get an erection. At the sight of your bulge, she decides to pull down your pants, which she laughs somewhat at, and then she decides to start tickling your crotch in such a way that it sort of gradually turns into a handjob. You feel violated and try to tell her that she's crossed a line, but you can't stop laughing so you can't get the words out. You ejaculate and as your cum arcs through the air her laughter stops for a moment and time seems to freeze as your semen lands on her face. She then wipes the semen off with her face and licks it.
"Mmm... your juice is megas delicious. Hahaha."