College girls that seduce guys to sex and during sex they kill them wat movie is this?

i cant remember when i first saw this movie but the girls were aliens or monsters and the seduce guys into having sex and when they have sex or just before the girls would show them who they really are and the would stick like a tube out of there body and stick it down the guys mouth and it would kill them... the one scene i remember is a girl tells a guy what she is and tells him that she will probably kill him and he did care he still wanted to have sex and she does her thing and the protagonist comes in and he knows what the girls are and he trys to save him but its too late... the guy survives for a little bit longer after they had sex but eventually dies... hopefully this helps into determining this movie title