He is rocking back and forth on all fours, Loki leaning over his back can probably see Thor's abused hole flexing repeatedly with his movements, large dollops of white cum sliding down his perineum, his sack and caking the insides of his thighs, while his lips are stretched around the engorged Jotun flesh.
When Loki spills again Thor is too slow, he can't swallow everything and chokes on the creamy fluid when it fills his mouth to the brim and rushes out of his nose. He collapses on his elbows, chest heaving and leaking ass still held high in the air, lapping desperately at the head of Loki's cock to catch every last drop.
Even thought Loki has already spent himself a countless number of times his cock has never been fully at rest, shifting from half-mast to full hardness in a matter of seconds during the night.
"More..." Thor begs from between his brother's legs, spasming hands clenching on Loki's thighs.
"Stay where you are."
Loki slinks behind his brother, the heavy spice of Frost Giant pheromones lingering in the air. His gaping hole is red and shiny with the thick Jotun seed, oozing out of him in a constant stream.
Thor turns his head, the right side of his face pressed in the sodden linens, pupils blown wide under heavy lids. He must make a truly obscene picture with congealed cum clinging at his beard and his legs spread wide like a bitch experiencing her first heat.
When Loki re-enters him with a loud squelch his mouth opens in a soundless moan, he feels like he has forgotten how to speak. Not that it would matter. The slaps of his brother's skin against his wet thighs, coupled with the slurping noises his hole is making around Loki's shaft, would probably draw out every other noise.
"Do not worry, brother. There's more. A lot more."
And Loki cums in him again. And again. And again.
Load after load, the strangely cold and viscous sperm is filling his rectum and opening his most inner ring of muscles with an insistent push.
He is so full that his bowels start to cramp and his abdomen feels distended when his brother comes in him a last time with a shuddering snarl. The heavy, round curve of his stuffed belly is dragging him down and making Thor collapse on his inflated stomach.
His insides clench trying to keep all the fluids in, but he is too tired and too full. In a cold, wet rush a flood of cum washes his crack and his upper legs. If his face was not already red with lust and exertion, he is sure it would be now from shame.

Loki's breathless snort of laughter drift to his ears from behind him and in an instant there are a couple of fingers shoved up his ass, violently scissoring and twisting, loosening his already lax hole and letting more seed leak out.
He wants to protest. He wants Loki to mount him again, to feel the head of his cock pressed deeply inside his eager throat, pumping is stomach full with cum. To feel the blue, grooved flesh stretch his burning opening raw. But he can't move.
Every part of his body is drained, even his cock has been soft for hours by now, the reddened glans peeking out from under his empty sack between his spread thighs.
"Such a cum-thirsty slut. Who would have guessed...?"
Where Loki finds the energy to speak, let alone mock him, still escapes Thor. He can hear him fisting his own dick furiously and then a scaldingly cold splash hits the curve of his back to drip on his fluttering anus.
"Look at you, hole clenching and unclenching like a mare's cunt, hungry to be bred." and Loki, Thor muses, probably knows what he is talking about.
It's with a mouthed 'please' that he tries to bring his trembling knees under him, lifting his rear, presenting himself for yet another taking, his spent cock swinging gently between in soppy thighs.
A shiver runs down his spine when Loki rubs his glans against his abused and inflamed opening, a contemplative hum on his lips.
He slaps one of his dirtied cheeks cruelly and the God of Thunder can do nothing but whine like a wounded beast. Slender fingers wrap in his sweat-soaked hair and Loki is breaching his drooling hole anew.
Outside the window, the Moon is sinking behind the mountains when finally Loki collapses over him, his cock still wedged deep inside his ass, locking everything inside, his full innards pressing deliciously and uncomfortably against his bladder and his prostate.
It's with a content smile on his face, that Thor lets sleep finally claim him.

Fin.