Bent over on the bed, on your back, eyes covered, wrists bound to your ankles, tits squished together nice and pretty, fully free-use strap bait, and your partner warms you up, starts off with a fairly normal size toy, maybe just a little bigger than you're used to, and you're leaking a massive puddle with every thrust into you, and moaning all sorts of horny nonsense... and then you hear the sound of a pump being squeezed and you feel the strap inside you thicken...
And it's definitely more than you've been able to take before!
You try and beg them to take it slow, say how much it is, your pussy isn't used to anything that big! And your clit is hammering in time with your heartbeat and you're shaking when they start rubbing it super fast while they keep fucking you...
Then, before you've even gotten used to the current size, they squeeze the pump again and you whine, oh fuckkkk that's WAY too much! You're starting to sob, overstimulated from the stretch and the attention on your clit, and your partner shushes you, tells you it's okay! And then they take the hand on your clit and use it to push your own teat into your mouth, holding it there so your're forced to suck on it.
All the while, they're still fucking you, and you can't do anything about it, and your brain finally starts to shut off when the pump squeaks again, and all you can do is take it...
Hours later, your partner undoes the release on the strap and steps back, leaving the toy still lodged in you, and then you're dazzled, blinking in even the dim bedroom light. Your partner is behind you, one hand on your tit, groping, and the other circling around the end of the toy inside you. You're held up by their shoulder and your wrists and ankles are still bound, so you're forced to watch in the mirror beyond the foot of the bed as the toy is finally pulled out of you... You cum hard, and the evidence of all the other orgasms forced upon you joins it, flooding the bed further as your hole flutters vainly, the muscles exhausted and stuck where they've been forced for the past few hours.
You're so open, and you finally look properly at the toy, still inflated at the size it was removed from you...
How THAT managed to fit inside you, you have no idea. It makes you feel light-headed just looking at it.
You're still mesmerised by the unreal girth of the toy when you finally look and see your partner has a fist inside you, and it's not until they open their fingers and drag their fingertips along your g-spot and up to your cervix that you realise that's the first thing you felt, even though they're wrist-deep inside you.