He wants to see just how far you'll go.

As you work Daddy's shaft he takes a tighter hold of your head and begins to control your movements more. You offer no resistance, you are his to use as he pleases after all. You can feel the twitch in his body that signals the approach of orgasm and you thrill in anticipation. You haven't been able to give Daddy much in the way of oral sex, every drop was poured into your womb until a pregnancy test came back positive, and it fills you with a pride only a good girl can feel when you manage to fully pleasure him with your mouth.

It's then that Daddy takes full control of your head, forcing you down on his cock so much your jaw aches and panic floods your brain. He isn't pulling back and you can't breathe.

"Don't struggle kiddo," he growls a warning, moving his hips and your head enough to keep pleasuring himself but not to let you breathe easily. "Keep as still as you can and be a good girl for Daddy."

'A good girl' the words are like a balm to your mind and you focus on keeping your teeth away from Daddy's cock and on maintaining your posture as best you can. You can feel a burning in your lungs and you head starts to spin but you stay in place, your hands clinging to your own wrists tight to stop them from moving in panic. Between your thighs you can feel the heat and moisture of your kitty as the throat fucking excites you further. You were born to be Daddy's ****, to be used by him and grant him pleasure is sole reason you exist, and the pressure of asphyxiation heightens your pleasure further, the air being sucked out of your empty little head.

Then without warning he pulls back, but you are ignorant to the chance to breathe. Daddy hasn't cum yet, you felt him twitch a lot but he hasn't cum. His grip on your head releases and without hesitation you lean forward and wrap your lips about him again. You won't let Daddy be unsatisfied. Without a single inhalation you drive his dick back down into your throat, wrapping your tongue about him and pushing him to the edge. With adoring eyes you look up at him as he grins like a hungry wolf before a lamb down at you.

Then, as blackness threatens the edge of your vision, he fills your throat with white.