Use the bucket!

"Just use that bucket over there! Turn it over, step on it, push your tits through! Easy!"

"Y...yeah, alright. I'll try that then!"

The topless girl grabbed the old and faded plastic bucket, turned it around and positioned it right in front of the transparent side. A bit nervous, she stepped on it and noticed that she now was at the perfect height for the task at hand. She pushed the little window up and locked it in place, the scorching hot outside air hitting her chest.

"Hope I don't get sunburnt doing this!" Amy muttered as she pushed her meaty bosom into the small opening.

"That's it, girl!" Tom cheered from the outside, "Stuff those suckers through!"

Their hands quickly found the little bit of flesh that was peeking out of the window, and soon they were pulling at her treasures hard.

"Ouch! Guys, slow down, please? It's a bit tight in here!"

"Don't worry, dear! We'll get those things through in no time!"

And indeed, only a few moments later, the bikers had ripped her tits right through the small opening. The eight bikers marveled at the luscious flesh pillows ballooning out of the little window, conveniently located and mouth-height for the taller men. Amy's breasts were now sitting completely outside, with the frame of the window squeezing the base of her breasts. They looked ripe and large, with a slightly rosy tint.

Tom took the liberty to be the first to enjoy the offerings and dove into the fantastic pair. His fingers found a nipple while his lips closed in on it's twin and he started to suck in earnest. Amy squeaked surprised after the first touch but then sighed with pleasure as the graybeard pampered her sensitive nipples.