sit close to her and finger her

"what you're doing is a handjob... and this is called fingering" then gently you introduce a finger in her pussy and rub her clit
"now i'm caressing your clítoris.. your pleasure center"
the girl is clearly excited and she's getting wet
"it feels warm"
"yes, and pleasurable isn't it?" she nods
"if i ever fuck you with my cock it may hurt you the first time but later you'll enjoy it"
trying to reward you for the feelings she starts stroking your cock hard, making it hurt
"shhh calm down, doing it too fast may make it hurt"
son both of you're cumming and your cum has covered her hand as the floor is covered with her juices
"you see? it felt great didn't it?"