As does Kristen's air supply

"GLKKK! GKKKKKKKK!"

Kristen gagged and quickly composed herself to start her reps, trying to strike a balance between going fast enough to get to 50 reps, but not too fast to burn all her oxygen supply. She proceeded to do reps but as she continued to go so, her gag reflex was starting to pick up steam, trying to make her push David's cock out from her Dick Sucking Lips.

Holy shit! I'm gagging harder than I used to!

Kristen buckled again before trying to compose herself, yet already the gigantic balloons on her chest called tits were bouncing to signify to David that this cunt was already burning up her air supply.

"GKKKKKKKK! GKKKKKKKK!" Not too much time later, each rep trigger her to gag and heave as her supply of air was already getting dangerously low, her muscles burning as she was soon performing anaerobic bench presses as her face turned red. She didn't even know how many reps she had done, as the air-deprivation was making her hands tingle and arms shake.

"What's the matter whore? Hard to work out when you've got my dick down your throat right? Looks like you might drop those weights if your not careful"

David was right, Kristen had stopped doing reps as her arms and hands burned from the lack of air and could barely hold the bar above her. In fact, she was getting weaker as the bar came closer to her face and neck.

"MUMMFH, GLCUK!"

Unable to speak and tell David to help her, Kristen strength failed her as she managed to stop the bar hitting her, but it started to push down on her neck!

"GACKGACKGACKGACKGACKGACKGACK!"

Kristen panicked as David grabbed the bar that was now pushing down on her throat, effectively balancing the weights but still throttling the slut. She tried to push it off but it seemed too heavy to move and the air-deprivation was getting even more serious. Her face was turning purple and her legs was starting flail about as she heaved and hurled on David's dick, which was now being squeezed even harder in Kristen's throat. Hopefully David would pull the bar off her before she was strangled by the weights.