When you are engaged in anal sex with a girl (or guy) and you ejaculate into your partners asshole (creampie) you take a straw and stick it in your partners anus and suck the sperm out.
Montez: "mmm..i cant wait till after school so i can stalk chad home and watch him in the shower then brutally rape him and give him a good ole slushee!"
A vagina that's had a load of semen shot into it anywhere in cold temperatures.
Note - semen shot into a vagina NOT in cold temperature a cream pie.
John McCain stuffed his cock far inside Sarah Palin and made a slushee that took a full 5 minutes to thaw out.