Slowly - Have him do his part

You're not about to let Darryl's incompetence get him off the hook. You press down against his face a little, and he murmurs something unintelligible into your pussy. Whatever it was, it doesn't matter. You turn your attention back to his cock, but rather than actually suck him off, you just idly play with it a bit. Occasionally you give it a little lick, so he can't claim not to have gotten his blowjob. Still, even Darryl is not going to cum from this any time soon. He knows that too, and doesn't appear very happy with it. He twists his head so he can speak clearly. "What are you doing, Cindy? Just suck it already!"

"Don't worry," you reassure him, "You'll get your blowjob. Just as soon as you get me off." "That wasn't part of the deal!" Ugh, pathetic. "Nope," you tell him, "But it's what's going to happen. So you'd better get to work, I don't have all day." Darryl grumbles a little, but he does start licking you again, a little bit more forcefully this time. Perhaps there is still hope, then.

Slowly, very slowly, a fire is building within you. Looks like he'll get the job done after all. Eventually. You keep teasing his cock with licks, kisses and caresses for a while. When you start actually getting close, your instincts take over, and you gradually begin putting in more of an effort. Darryl lets out a little grunt, and intensifies his own efforts as well.