On her back.

As you feel you're about to explode you quickly whip out your cock and shoot a hot stringy load all over Salma's back.
"OH BABY" she cries "IT'S SO WARM!!!"
Arch after arch of sticky cum flies across her skin,splashing on her ass,her back and even up into her hair.
"Oh Daddy" she purrs "That feels so good"
After awhile the last drop drips out of your tip and into the crack of her ass,she reaches around,scoops it out and licks it off the tip of her finger.
"Ummmmmmm" she smiles "Yummy!"
Slumped you watch as Famke licks Salma clean and then when they have both dealt with your sticky cock they look at you and say in unison "So,do we have a deal?"