You grab them

Keeping the act together, you move a trembling hand towards the offered dozen balloons and closes your fist around the ribbons. Stacy doesn't let go immediately, giving you a 'cut the bullshit' stare before releasing the merchandise.

In an instant, your arm is once more pulled up towards the ceiling, promptly followed by the rest of your body as your shoes loses contact with the floor. The lift is strong enough that, in less than three seconds where you scream your heart out, your bouquet bounces off the ceiling with you now dangling over 12 feet above the ground. "Stacy! What the hell's going on!"

You look down at the stunned clerk looking up at you, her mouth agape. "I-I-I don't know! T-this is impossible! Balloons can't just do... THAT!"

"Well, they are! Help me down, please!" you plead, kicking your legs futilely.

"O-of course! I... I'll be right back, stay right there!" She swiftly hurried off somewhere else.

You're doing wonderful, honey, Ava's voice whispered in your ears. Time to shift it up a gear.

You feel yourself getting lowered gradually. The balloons above you gently float down and towards the counter while you're carried along in the process. Stacy appears once again. "I couldn't find the balloon retrieval... stick... to..." Her voice dies in her throat as she sees you drifting over the counter.

Your body is turned around while a flat purple party balloon levitates and sets itself on the nozzle of the helium tank. The unmistakable hiss of helium getting expelled in a balloon followed suit as the plastic nozzle of the helium tank pressed itself down, the toy swiftly expanding in size just below you. You both stay silent, with Stacy's jaws hanging slack and her eyeballs attempting to escape her eyes sockets.

Once the purple balloon grows to two feet across, you feel yourself getting lowered towards it. Your legs are forced apart by an invisible force and, with a strangely loud squeak, your ass indents the still self inflating orb. The hiss increases in volume as you feel your impromptu mount stretching bigger, faster, the thing creaking and squeaking loudly. The cluster you hold onto escapes your grip before dividing themselves into two equal groups of six. Each half ties themselves to one of your armpit.

Only once the balloon under you grows to over four feet wide does the hissing stop as the toy's neck releases the helium's nozzle and ties itself up tightly with a loud twang. You begin lazily drifting through the air atop your big squishy mount towards the still stunned clerk who, when she notices you approaching, begins stepping back only for her back to collide against the wall, stopping her escape. The next instant, your mount squishes against her stomach, conforming to her body, preventing her from getting away. She soon tries to shove the balloon away, but to no avail. It held her back, the purple mass not caring about any of her attempts.

Out of nowhere, she suddenly perks up. "Who said that?" she exclaims loudly, looking around haphazardly. You safely guess your girlfriend is telepathically in contact with the trapped clerk. "Well, I d–" She stops herself. Slowly, she lowers her sight to your penis which is casually pointing towards her face, a blush spreads on her face. "I... I don't know..."

Another half a minute passes while the clerk just stares at your penis, clearly mentally debating something. You simply wait on your balloon with your legs spread apart. Ava was doing something for sure. Thus, you waited patiently.

Eventually, the clerk slowly lowers her face between your legs before gently kissing the tip of your glans. The delicate contact sends a very pleasant shock wave through you. Your body sends itself backwards, fully slouching yourself on the surprisingly comfy latex as the clerk begins servicing you liberally. Soon, your tip gets surrounded by her moist lips as she swirls her tongue around your glans, making you moan. You also detect some light suction.

Soon, you feel yourself leak and, a moment after, the woman releases a deep, throaty moan, freezing on the spot. You wonder what happened, but can't think about it long enough before she deepthroats your entire dick instantly. Feeling her whole mouth and the back of her throat with no warning, you were not prepared to hold back as your dam bursts.

The clerk doesn't seem to mind at all. Her nose still presses against your stomach as your orgasm enters her directly, which she greedily swallows as if she was stuck in an desert and you are the water casket she just happened upon. Shots after shots enter her, her seal on you never faltering until your orgasm dies down. Only when she's certain that you're done does she retreats with a satisfying pop. Your dick is squeaky clean. She releases a loud sigh that shows her mouth is empty, proof she didn't leave a single drop go to waste. She rested her face on your leg as she happily pants.

Let's see if she wants to ride you, I bet you'd love to get your hands on that ass, came Ava's voice in your mind.