(NSFW) How do you say yes to a girl (offering this particular offer)?

(((Ok in case you didnt see the NSFW warning, which includes NSFChildren, its NSFW or C)))

Lets say a friend of yours wants to know how he can say yes to this offer from a girl: “David, if you work a double for me on Saturday, which I know you hate, I will administer fellatio to you”.

They are the same age, same maturity level, have the same thing in mind, and have had for a while, openly/jokingly/in hopes, but also have a love/friendship for each other thats been developing for a while, they always have fun together, they care about each other, and any intimacy of any kind would also mean something because of that. So is saying “Freaking HELL YES!!!” all Gung Ho the wrong way to say yes when there is also that element of caring emotions involved?