A teenager thriller or horror quite simillar to the Faculty(1998).

Teenagers(guys) die after having sex with girls who actually turn out to be aliens who feed or reproduce causing the victim to die of freezing after the climax. One of them falls in love with the CC’s best friend and tries her best not to kill him stating that if she doesn’t want it he won’t die but the guy dies anyway and that is played around as a big drama moment in the movie.

IIRC the openning scene takes place on the cemetry.

Watched it in the second half of 2000’s