A technique of pulling out and then compressing air into a vagina/anus. It takes time and certain skills to perform this act. When done correctly, you can make a partner flatulate on command or perform a Minnesota Log Chute.
Dude, I cum-pressed her until it looked like she had a thirst ass cheek... then she blew, and that's why i got pink eye. Be careful, the cum-pressor is dangerous.