Drop to your knees and use your mouth to help the daddy out.

You drop to your knees in the filthy alley and take the daddy's cock into your mouth with eagerness.

"Oh yeah," the daddy says, and wraps his rough hands around the back of your head.

You swirl your tongue around his foreskin as he hardens, and before long, you're sucking the full length of his stiff cock. He grips your head tightly, sliding his cock in and out of your mouth with an almost lazy pace, taking his time. You grip his thighs, and he guides his cock deeper and deeper into your throat with each stroke. By the time he's breathing heavier, spit has collected all along your lips, and the salty taste of his precum is rich in your mouth. His thickness takes some getting used to, but you enthusiastically suck and slurp at his cock, feeling like a dirty whore in the alley.

Finally, he pulls his dick free from your mouth, and shoves your head backwards, so you fall back against the dumpster a little, awkwardly leaning there on your knees. He grips his cock, and jerks himself rapidly. Ropes of cum blast from his dick, the first largest spurt hitting your face and trailing all the way down your shirt, the next three smaller spurts mostly splattering on your shirt. He jerks for a moment longer, and when the last spurt drops on your shirt, he winks down at you.

"Mission accomplished, slut," he says, and tucks his cock back into his jeans. He goes back into the bar through the back door, and you sit there for a moment, panting.

You realize you can't go back inside with cum spattered all over your face and shirt, so you rise shakily, and make your way out of the alley, for the long walk home, rubbing some of the cum off your face on the rare dry portions of your shirt.

Quite the birthday.