Yes

Reluctantly, you say yes, but only out of fear of going into a coma. It is reversible, if you get enough doses of cum, but with all the other options available, not many people donate to hospitals anymore. Your dad would likely donate, but, your brother would probably avoid spending doses on you if he could get away with it. Either way, you doubt that they alone would be able to supply enough to make a difference.

You lay face-down on the pavement, and place your panties in your ass, trying to align the main part of the fabric so it will catch most of the cum. The man roughly mounts you and starts fucking you with more intensity than before. He positioned himself so that most of his weight is pressing you down into the pavement, constantly rubbing your nipples against the rough pavement. After a few minutes, he begins roughly groping your breasts and pinching your nipples, which causes you to briefly scream out, but you quickly stop yourself. He begins alternative between rubbing your breasts on the pavement and groping them every few minutes, while continuing to violently fuck your ass. After several repetitions of this, he forcefully pulls your arms back, which in turn causes your head and upper body to lift up from the pavement. Though this slightly relieves the pain in your breasts, he begins fucking your ass much more forcefully, slamming his whole body into you with each thrust. You can tell he is very close to orgasm, and try to speed up the process by clenching the muscles in your anus as much as you can. After about another minute, you feel the cum squirt out into your ass.

He then gets off you, and says "Eat up little cumslut." You then see him pick up a video camera off of his car, which you realise has been recording you the whole time. You know you aren't in a good position to protest his videotaping, so you keep quite. You go to pull the panties out of your ass, and realise that they were pushed far back and wadded up by him fucking you. You are able to reach in and get them out, but they mostly have shit and you see only a little cum on them. You stare at them for a second, hesitating to put them in your mouth. The man says "Aw, little cumslut didn't get as much cum as she wanted. Tell you what, why don't you wipe off my dick with those panties, then clean it with your mouth, then maybe you can eat your little bit of cum." While saying this, he picks you up and places you on your knees. You use the panties to wipe off his now-filthy cock, which had a bit of semen left on the tip. He then shoves your face down onto his cock, and begins facefucking you. After about five minutes, he holds your head all the way down on his cock for nearly a whole minute while pinching your nose shut with the other hand.

Next, he shoves you back down onto the sidewalk, and grabs your hand, directing it to pick up the panties and shove them in your mouth. He says "Ok cumslut, suck your panties clean and I'll let you try to get some more cum from your ass with them." You hastily begin licking the panties inside of your mouth, trying to get off all the shit and making sure to get the few drops of cum in the mix. After you have gotten most of the shit off them, which leaves an awful taste in your mouth, you spit them out. The man tells you, "Now hold them in your hand and I'll help you clean up your asshole and get any of the cum in there." You reluctantly do as he says. He once again grabs your arm, but now forces your fist holding the panties into your asshole, and begins roughly directing it around your asshole. You are thankful he is at least seemingly trying to rub different areas, hopefully picking up some of the cum, and not just **** you to fist yourself. After nearly five minutes of this, he pulls your hand out of your ass. Your hand and the panties are covered with shit, though you do see a bit of cum on the panties. He tells you "Little cumslut, you aren't allowed to eat the cum off your panties until you clean up your fist."

You do as he says, licking off all the shit off your fist, almost vomiting several times. He repeats the process of having you clean your panties with your mouth, but this time you taste quite a bit more cum, though also taste a lot more shit. After this, he gets in his car, and drives away. You put back on your panties, which are now dripping wet from saliva. You could try to go to school and try to get a uniform on the way, though you think it would just be easier at this point to go to the mall and buy a new uniform, and just skip school today.